lea!!!] Effects Research Series DIETARY SUBACUTE TOXICITY OF ETHYLENE THIOUREA IN THE LABORATORY RAT Health Effects Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Research Triangle Park, North Carolina 27711 ------- RESEARCH REPORTING SERIES Research reports of the Office of Research and Development, U.S. Environmental Protection Agency, have been grouped into nine series. These nine broad cate- gories were established to facilitate further development and application of en- vironmental technology. Elimination of traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The nine series are: 1. Environmental Health Effects Research 2. Environmental Protection Technology 3. Ecological Research 4. Environmental Monitoring 5. Socioeconomic Environmental Studies 6. Scientific and Technical Assessment Reports (STAR) 7. Interagency Energy-Environment Research and Development 8. "Special" Reports 9. Miscellaneous Reports This report has been assigned to the ENVIRONMENTAL HEALTH EFFECTS RE- SEARCH series. This series describes projects and studies relating to the toler- ances of man for unhealthful substances or conditions. This work is generally assessed from a medical viewpoint, including physiological or psychological studies. In addition to toxicology and other medical specialities, study areas in- clude biomedical instrumentation and health research techniques utilizing ani- mals but always with intended applicStion to human health measures. This document is available to the public through the National Technical Informa- tion Service, Springfield, Virginia 22161. ------- EPA-600/1-77-023 May 1977 DIETARY SUBACUTE TOXICITY OF ETHYLENE THIOUREA IN THE LABORATORY RAT by Ralph I. Freudenthal Battelle Columbus Laboratories 505 King Avenue Columbus, Ohio 43201 Contract No. 68-02-1715 Project Officer Ronald L. Baron Environmental Toxicology Division Health Effects Research Laboratory Research Triangle Park, N.C. 27711 U.S. ENVIRONMENTAL PROTECTION AGENCY OFFICE OF RESEARCH AND DEVELOPMENT HEALTH EFFECTS RESEARCH LABORATORY RESEARCH TRIANGLE PARK, N.C. 27711 ------- DISCLAIMER This report has been reviewed by the Health Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the U.S. Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. ii ------- FOREWORD The many benefits of our modern, developing, industrial society are accompanied by certain hazards. Careful assessment of the relative risk of existing and new man-made environmental hazards is necessary for the establishment of sound regulatory policy. These regulations serve to enhance the quality of our environment in order to promote the public health and welfare and the productive capacity of our Nation's population. The Health Effects Research Laboratory, Research Triangle Park, conducts a coordinated environmental health research program in toxicology, epidemiology, and clinical studies using human volunteer subjects. These studies address problems in air pollution, non-ionizing radiation, environmental carcinogenesis and the toxicology of pesticides as well as other chemical pollutants. The Laboratory develops and revises air quality criteria documents on pollutants for which national ambient air quality standards exist or are proposed, provides the data for registration of new pesticides or proposed suspension of those already in use, conducts research on hazardous and toxic materials, and is preparing the health basis for non-ionizing radiation standards. Direct support to the regulatory function of the Agency is provided in the form of expert testimony and preparation of affidavits as well as expert advice to the Administrator to assure the adequacy of health care and surveillance of persons having suffered imminent and substantial endangerment of their health. The significance of the occurrence of residues of pesticides or metabolites of pesticides in or on plants destined for human consumption must be considered with respect to its ultimate impact on human health. The present study evaluates the effect of the presence of ethylenethiourea (ETU) in the diet of a mammalian model test system. ETU is the major metabolite of a class of fungicides (ethylenebisdithiocarbamates) and the toxicological hazard associated with this biologically active metabolite as a residue in food is under intensive investigation. An evaluation of the health hazards associated with the presence of ETU in food includes the primary effects on the thyroid and liver as well as several associated biochemical parameters in an effort to determine a dietary level which might be safe for man. John H. Knelson, M.D. Director, Health Effects Research Laboratory iii ------- ABSTRACT Ethylene thiourea (ETU) was fed to groups of rats at 0, 1, 5, 25, 125 or 625 ppm for up to 90 days. Other groups of rats received either propylthiouracil (PTU; 125 ppm) or amitrole (50 ppm) in their diets as positive controls. Only those rats which received ETU at 125 or 625 ppm and those ingesting PTU or amitrole demonstrated a measurable toxic response. This toxicity was reflected as an alteration in thyroid func- tion and a significant change in thyroid morphology. Ingestion of 625 ppm ETU, or 125 ppm PTU resulted in very substantial decreases in serum triiodothyronine (T-3) and thyroxine (T-4). Marked increases in serum thyroid stimulating hormone (TSH) levels were found in the 625 and 125 ppm ETU rats, the 125 PTU rats and the rats receiving amitrole, at each time point this hormone was measured. A decrease in iodide uptake by the thyroid was also found in the rats which ingested 625 ppm ETU. While a statistically significant increase in serum T-4 and degree of thyroid hyp.erpla.sia was observed for the rats ingesting 25 ppm ETU for 60 days, normal thyroid hormone levels and thyroid mor- phology was found in the rats on 25 ppm ETU for either 30 or 90 days. Bas_.ed on. biochemical and microscopic changes examined, the no-effect level for dietary ETU ia this 90rday study is considered to be 25 ppm, equivalent to an average intake ranging from 19.5 mg/kg body weight at Week 1 to 12.5 mg/kg body weight at Week 12. iv ------- CONTENTS Foreword iii Abstract iv Figures vi Tables vii Introduction 1 Experimental 2 Materials 2 ETU Purity Analysis 2 Thyroid Function and Control 2 Evaluation of Test Kits 3 Methods 4 Results 5 References. .. -. 9 ------- FIGURES Number Page 1 MS Analysis of the ETU used as the test chemical 11 2 MS of the ETU used as the test chemical 12 3 Diet consumption 13 4 Test chemical consumption 14 5 Body weight gain 15 vi ------- TABLES Number Page 1 ETU Protocol Design 16 2 Tissues Removed and Weighed During Necropsy 16 3 Thyroid Hormone Levels - After 30 Days on Study 17 4 Thyroid Hormone Levels - After 60 Days on Study 18 5 Thyroid Hormone Levels - After 90 Days on Study 19 6 Free Thyroxine Index 20 7 Weekly Diet Consumption 21 8 Weekly Test Chemical Ingestion 23 9 Weekly Body Weight Gain 24 10 Organ Weights Obtained at Necropsy 26 11 Organ Weight:Body Weight Ratio 28 12 Organ WeightrBrain Weight Ratio 32 13 Abnormal Changes Observed for Liver, Skin and Thyroid .... 36 14 Grading of Deeree of Hyperplasia From Microscopic Appearance of the Thyroid Gland 37 15 Thyroid Hyperplasia Observed in ETU Test Animals 38 16 Changes in Thyroid Morphology in Rats Which Ingested 625 ppm ETU for Ninety Days 39 vii ------- INTRODUCTION The salts of ethylenebisdithiocarbamic acid (EBDC) have been exten- sively used against a variety of pathogenic plant fungi. A principal impurity and degradation product of the EBDC fungicides is ethylene thiourea (2-imidazolidinethione; ETU). ETU has been identified as an impurity in commercial EBDC formulations (1, 2). It has been reported to occur as a result of metabolic (3, 4, 5) and chemical (6, 7, 8) alterations of the commercial fungicides. ETU has been identified on a number of different crops which had been field-sprayed with a commer- cial formulation of EBDC (9, 10). Cooking of foods containing EBDC residues also results in the formation of ETU (11, 12). Early studies evaluating the toxicity of the EBDC fungicides reported a major effect to be thyroid hyperplasia and neoplasia (13, 14, 15). The toxicity of ETU has also been studied and found to be essentially similar to that of the parent fungicide, producing thyroid neoplasia in rats (16, 17) and liver tumors in mice (14). In these published reports, recorded parameters consisted of body weights, organ weights, food con- sumption, ^ I uptake, and terminal histopathology. In the ETU subacute toxicity study reported herein, thyroid hormone level measurements were also made to determine at what dietary dose level ETU causes thyroid hormone alterations and to establish a dietary concentration which does not induce thyroid changes leading to hyperplasia. In addition, it was hoped that a relationship between altered thyroid hormone levels and thyroid hyperplasia could be established. ------- EXPERIMENTAL Materials Sprague Dawley-derived cats* were purchased.front Charles River Laboratories; (W^liningtBwi- Massachnsettsr)-.. E0J- (estimated? to?be-->95h percent pure) was obtained front the: Aldrich Chemical Company (Milwaukee,. Wisconsin),, and prap§rlth±aurac±l (FEU) and antitroie- (3^-aminol-,2,4 triazole)' were- purchased? fram*- the1; Sigma* Chemical. .Company/ (St.. Louia^ Missouri)r. 1^1 f or i the- ehyraidt iodine* uptake: studies; was. obtained, from* New England^Nueleat (Btkafcgm^Ma.R.<₯afthusefcfca).^ . CommprriaT,; test .,kfIrs, .fan measuring- serum thyroxiner (fT~4^ an-d!. thg^cai-d- binding: g-lobuitnr (XB&^> were-: purchased.front.Nueleat.Medical. Laboratories» Inc.. (Dallas.,, Texas),^ rriiodothyronine- (T1): Mts.werff. obtained, fixrar^DiagnastLCSLFrodiiets Corporation^ (Ixss-Angeles.^,CaJifbJcmiaOfe.- Initiai. serunn TSH, measurements^. were perfG,Emed^wifehT>Mtsj pusEchased^faEomixBeckmait InstarametttSj.: Incr^. (Fullerton>, eaMfd.rffia>. Shortly afterr tMs? study began; the speeif± city of thei antiserufflT for'human? ISffi wasechangede andc. thfr-measttrfc o«f^ rafe . TSH was no longer accomplished.. TSH kits from ICN'Medi-cai, Phaiina^arDia^iaffstics andt CaiLbioeheiih, were purchased.and. evalua'ted as possible substitutes; for-measuring cat: TSHv Only the: Galsbiachenb T'SBi RiEAL Mfc pxoxedL suitable,,, amdi. it. was= usede at the end; of this study. TSH-was-not measured during: most. o.£. the. study,.. ETU Purity-Analysig The ETIT used in, this study was: anaihy.zed by mass; sipecfeEoscopy and: nuclear magnetic resonance .spectrometry- (NMR):». Direct prober high resolution, mass spectroscopy showed: a strong: parent ion. at,m/e 103. This is shown in:. Figures: 1- and 2... It wasi estimated: tharough the-use. both l^c and 2ft NMR. spectros;copy that ETU was 96..8. percent, pure.. Thyroid Euacticab and Coatrol. Thyroid hormone is. biosynthesized .in .the- thyroid: gland by; the iodinatiom of tyrosine^ lodatyrosinea are coupled to_ fornL..T-3 and T-4. These active hormones are~reieased into-rthe- bloodstream" and-are -dist-ri- -- buted throughout the-body where, they, regulate, metabolic., processes. Hormone synthesis: and. release- is. eoatrfflled by a peptide which, originates in the anfeer-iot lobe- ofc the. pituitary..,, the., thyroid stimulating, hormone ------- (TSH). Pituitary secretion of TSH is, in turn, regulated by two factors, a hormone released by the hypothalamus called thyrotropin releasing hormone (TRH) , and the concentration of free thyroid hormones (T-3 and T-4) in the interstitial fluid which bathes both the pituitary and hypo- thalamus. Increased serum thyroid hormone concentrations suppress secretion of TSH while decreased hormone levels augment TSH release, providing for a steady-state thyroid hormone concentration. Recent studies indicate that thyroid hormone blocks pituitary response to TRH. As the serum levels of T-3 and T-4 fall below a threshold concentration, the TSH- secreting cells of the anterior pituitary become responsive to TRH and secrete TSH which, in turn, raises serum thyroid hormone levels. This feedback control system is designed to provide a constant supply of thyroid hormone to peripheral tissues, where it acts as a regulator of cellular metabolism. Chemical substances that impair the synthesis or release of thyroid hormone cause hyperplasia of the thyroid gland. Continued exposure to antithyroid chemicals results in the transformation of the hyperplastic tissue to a malignant form. It is now well documented that chemicals altering thyroid function can initiate thyroid neoplasia (18, 19). Chemicals which impair the synthesis or release of TSH from the pitui- tary can severely affect the feedback control system which regulates serum T-3 and T-4 levels. In summary, altered thyroid function can result from the action of a chemical on iodine uptake and incorporation, synthesis or release of thyroid hormones, synthesis or release of TSH, or inactivation of receptors activated by either TSH (at the level of the thyroid) or by thyroid hormone (at the pituitary level). Using commercially available test kits, the serum concentration of T-3, T-4, TBG and TSH can be measured. 125 j uptake can be measured directly. The Free Thyroxine Index (FTI) was calculated and is reported for each group. The FTI is a measurement of free serum T-4. While the T-4 level, measured by the T-4 radioimmunoassay kit, is influenced by TBG concentrations, the FTI is a measurement of the amount of T-4 free in the serum, independent of the serum TBG concentration. The formula used to calculate the FTI is shown below: Evaluation of Test Kits We have previously shown that certain chemically induced alterations in thyroid function in rats could be measured using commercially avail- able kits. We reported serum T-4 and TBG (T-3 binding) levels and 125I uptake by the thyroid (20) . Prior to the initiation of this ETU subacute ------- toxicity bioassay, we evaluated a new f-3 kit produced by Diagnostic Products Corporation (Los Angeles, California), and a TSH kit from Beckman Instruments (Fullerton, California). The T-3 diagnostic kit quantitatively measures total serum T-3 by radioinununoassay. One hundred microliters of each serum sample (or standard) is mixed with an equal volume of 125i labeled T-3. Upon addition of the T-3 specific antibody, the endogenous serum T-3 and the radioactive T-3 compete for binding sites. This reaction takes place in the presence of ANS (anion-8-anilino- 1-naphthaline sulfonic acid) which blocks the interaction of T-3 with other serum proteins. A second antibody, goat antirabbit gamma globulin, is added to separate the free serum T-3 from the bound T-3. This solution is well mixed and incubated at 37°C for 15 minutes. An ice cold solution of 6 percent polyethylene glycol is then added to help precipitate the antibody bound T-3. Following centrifugation (3,500xg; 20 min.), the supernatant containing the free T-3 is decanted and the antibody bound T-3 precipitant is counted. A five point standard curve is constructed and serum T-3 levels are determined from this curve. The Beckman TSH diagnostic kit quantitatively measures total serum TSH by radioimmunoassay. The procedure is similar to that described above for the T-3 test. Serum from rats pretreated with amitrole was evaluated for T-3 and TSH levels and this was compared to values obtained from control serum. Unfortunately, after the ETU subacute tox'icity study began, Beckman switched to a new antiserum with increased specificity for human TSH. This kit would no longer measure rat TSH. Therefore, TSH kits from other commercial sources were purchased and evaluated as possible alternates. The kit produced by Calbiochem contains a relatively nonspecific TSH antiserum and will measure rat serum TSH levels. Unfortunately, this was not confirmed until near the end of the study and for this reason, TSH values are available for only very few groups. Methods ETU, PTU, or amitrole was added to corn oil and then incorporated into powdered rodent feed(l) using a twin shell tumble blender. The final corn-oil concentration in the blended f-eed was 1 percent. The test diets were prepared fresh weekly. The dietary levels of ETU were 625, 125, 25, 5 and 1 ppm, PTU was 125 ppm and amitrole, 50 ppm. These dietary levels of PTU and amitrole were previously shown to produce significant antithyroid effects (21, 22). A control group received powdered diet containing 1 percent corn oil. Each of the seven dosage groups contained 60 male and 60 female rats. The control group contained 72 male and 72 female rats. The animals were placed on study as out- lined in Table 1. Ralston Purina Company, Richmond, Indiana. ------- At 30-day intervals, 10 rats of each sex from each test group were sacrificed and serum T-3, T-4, TBG and TSH concentrations were measured. These rats were also used for necropsy. The remaining 10 rats of each sex per group were used for thyroid ^->I uptake studies. Each rat was individually caged throughout the study. Body weight and food consump- tion was determined weekly. Each rat was toe-punched at the start of the study for permanent identification. The 10 tissues removed during necropsy are listed in Table 2. Due to excessive salivation and abnormal skin-hair coat development at the 625 ppm ETU level, skin and mandibular salivary glands were also removed during necropsy from the rats which received the high diet. The thyroid gland and liver were examined microscopically in all study groups. These two tissues were fixed in formalin imbedded in paraffin, sectioned (6 microns) and stained with Hematoxylin-Eosin. The remaining tissues were stored in 10 percent buffered formalin. RESULTS The rats which received 625 ppm ETU showed clinical signs of poisoning by the eighth day on study. Excessive salivation, loss of hair or failure to replace normal hair loss, rough and bristly hair coat, and scaly skin texture was observed. Ingestion of ETU was calculated and found to range from 11.7 to 15.2 mg/day in female rats to from 13.0 to 17.3 mg/day in male rats. Table P shows data on the weekly consumption of ETU and other chemicals by all animals on study. Fourteen of the 40 rats on the 625 ppm ETU 60-day study died between days 40 and 50 of the study. Only one rat from the 90-day group died. The rats receiving 125, 25, 5 and 1 ppm ETU, control diet, 50 ppm amitrole or 125 ppm PTU showed no adverse clinical effects. Consistent with the observable clinical changes, several biochemical changes were noted. Rats ingesting ETU at 625 ppm showed a significant decrease in iodine uptake. The percent T-3 bound to TBG was lower than normal at the 30- and 90-day evaluations. Serum concentrations of T-3 and T-4 were also very substantially lower than the levels obtained for the control rats. The serum TSH concentration for the 625 ppm rats, measured only at the time of the 30-day evaluation, was increased to more than twice the serum TSH concentration observed for the control rats. Significant differences in free T-4 were also found, as determined by the FTI. The rate of iodine uptake, the percentage of T-3 bound to TBG, and the serum T-3 concentration in the rats receiving 125 ppm ETU were not significantly different from the control group. However, a statistically significant decrease in total serum T-4 concentration and in free serum ------- T-4 measured at the 30-, 60- and 90-day evaluations was observed. The serum TSH concentration in the 125 ppm ETU rats at 30 days was approxi- mately three times the concentration measured in the control rats. With one exception, there were ho significant measurable differences in iodine uptake, T-3 binding to TBG or serum T-3, T-4 arid TSH levels in the rats receiving ETU at either 25, 5 or 1 ppm for 30, 60 or 90 days. The rats ingesting 25 ppm ETU for 60 days showed a statistically signifi- cant increase in serum T-4 concentration. This was not evident at 30 or 90 days. After 30 days of amitrole ingestion, very significantly decreased serum T-3 and T-4 levels were observed. The female rats from this group also had a decreased percent of T-3 bound to TBG. Both the male and female rats had an increased serum TSH concentration. In a previous report (EBIS toxicity study), we showed that ingestion of 50 ppm amitrole for four 'days resulted in a significant decrease in iodine uptake and T-4 serum concentrations. While the decreased T-4 levels are still found after 30 days of amitrole ingestion, iodine uptake appears to have returned to normal, probably as a result of biological compensation. At 60 and 90 days, normal values for all of the thyroid function measure- ments were noted. The rats which received PTU had decreased serum T-3 and T-4 con- centrations at 30, 60, and 90 days. The serum TBG level was affected only in the 60- and 90-day test groups. Since the PTU study was added after the ETU study had started, TSH values were obtainable for the 60- and 90-day PTU test groups. Both groups had markedly elevated serum TSH levels. Tables 3, 4 and 5 list the percent iodine uptake, TBG, T-3 and T-4 concentrations after 30, 60 and 90 days on study, respectively. Also included in these tables are the values for the amitrole and PTU posi- tive controls. TSH values are given for those test groups in which it was measured. The calculated FTI for each test group is shown in Table 6. Diet consumption for all groups is shown in Figure 3. With the exception of those rats receiving 625 ppm ETU and those ingesting 125 PTU, there was no significant difference in feed consumption. A 30 percent to 40 percent reduction in food consumption was observed in the rats on the 625 ppm ETU and 125 ppm PTU test diets, compared to control animal con- sumption levels. The average weekly feed consumption for each test group with the standard deviation is listed in Table 7. The amount of ETU, PTU or amitrole consumed per week is shown in Figure 4. The average amount of each test chemical consumed along with the standard deviation is listed in Table 8. . ------- Individual body weights were recorded weekly throughout the study. Table 9 summarizes the body weight data (group mean ± S.D.). Figure 5 shows the weekly body weight gain for each dietary level. Only those rats which receive 625 ppm ETU or 125 ppm PTU test diets showed a marked decrease in body weight gain. No difference in body weight gain was observed for those rats which received ETU at 125, 25, 5 or 1 ppm, or amitrole, as compared to the control group. At the conclusion of the study, gross necropsies were performed and certain organs were removed and weighed (see Table 2). Table 10 lists the mean organ weights and standard deviation for each group. There were no significant differences in organ weights in those rats fed 25, 5, 1 and 0 ppm ETU. However, thyroid hyperplasia was observed in all animals which received 625 and 125 ppm ETU, 125 ppm PTU or 50 ppm amitrole in their diet for 30, 60 or 90 days. The organ-weight-to-body-weight ratios were calculated (Table 11). The spleen-to-body-weight ratio for the rats which ingested 625 ppm ETU is significantly decreased while the ratios for the thyroid, brain, kidneys, testicles and pituitary are significantly higher than the corresponding control values. Increased thyroid-to-body-weight ratios were also found for the rats which received 125 ppm PTU, 50 ppm amitrole or 125 ppm ETU (Table 11). Organ-weight-to-brain-weight ratios were also calculated (Table' 12). no significant differences were found between rats receiving 125, 25, 5, 1 and 0 ppm ETU. For those rats ingesting 625 ppm ETU, the ratio of heart, spleen, kidney, adrenals (female) and ovaries-to-brain- weight was significantly decreased and the thyroid-to-brain-weight ratio was significantly increased compared to control values. The thyroid-to- brain-weight ratios in the rats which received 125 ppm ETU were also significantly increased in size at 30, 60 and 90 days. An increased thyroid-to-brain-weight ratio was the only significant organ-to-brain-weight ratio change found in the 50 ppm amitrole test animals. The animals which received 125 ppm PTU for 30, 60 or 90 days showed a very significant decrease in organ-to-brain-weight ratios for heart, spleen, kidney, ovary, liver and adrenals. These animals had a very significant increase in thyroid-to-brain-weight ratios compared to the control values. The organ-weight-to-brain-weight ratios for the rats which received amitrole and PTU are listed in Table 12. Gross examinations revealed the majority of the rats which received ETU at 125 or 625 ppm, as well as those animals which received PTU or amitrole for 30, 60 or 90 days had enlarged red thyroids. Grossly visible patterns of centrilobular congestion were present in a few random rats fed amitrole or ETU. A summary of gross changes is presented in Table 13. ------- Microscopic examination of tissues was restricted to thyroid and liver. The thyroids were graded for degree of hyperplasia using a slight modification of the procedure of Astwood (23), and as defined in Table 14. Varying degrees of thyroid microfollicular hyperplasia resulted at feeding levels of ETU above 25 ppm (Table 15). Relatively mild changes were noted in animals fed 125 ppm ETU for 30 days as compared to the moderate changes observed in the rats fed 625 ppm ETU for the same time period. Marked thyroid microfollicular hyperplasia and reduced colloid formation were found in animals fed amitrole or PTU for 30 days. At 60 days, the rats receiving the three highest levels of ETU (625, 125 and 50 ppm) and the amitrole treatment group showed moderate thyroid hyperplasia as compared to the 60-day PTU group which was more marked in its thyroid hyperplastic response and reduced colloid production. Ninety days of dietary exposure to 625 ppm ETU also resulted in microfollicular hyperplasia but not as severe as seen with PTU in the same time period. Numerous changes ranging from adenomatous hyperplasia of follicles to what appear to be true solid adenomas were present in the thyroids in the 625 ppm ETU group. Table 16 categorizes the hyper- plastic thyroids from the 625 ppm ETU test group into either solid adenomas, cystic adenomas, adenomatous change or cystic-like follicles. No adenomas were observed in the thyroid sections taken from the other dietary groups. No liver tumors werei observed in the rats at any dosage level of ETU or in those animals which received PTU or amitrole. The majority of the livers examined microscopically had mild centrilobular changes which can be described as follows. Portal triad areas have a smooth sheet of hepatocytes cut relatively across the nucleus and cyto- plasm at about the same level giving well defined cell boundaries and cytoplasmic proportions. As one approaches the mid-zonal area and pro- gresses into the centrilobular area of small central veins, the pattern changes to less distinct cell borders of swollen cytoplasmic material with fewer apparent nuclei. The chord pattern is less distinct and.there is a mild increase in small.polyploid nuclei. The general appearance is that of increased cytoplasm, fewer nuclei and less orderly hepatic chords. The data presented in this report show no significant measurable adverse effects of dietary ETU at dosages of 5 ppm and below. Signifi- cant toxic responses, observed as altered thyroid function and changes in thyroid morphology, resulted from the ingestion of ETU at 125 ppm or 625 ppm for 30, 60 or 90 days. The observable effects at 25 ppm were noted only at the 60-day interval and were not seen at 30 or 90 days. Based on these data, a dietary no-effect level in rats might be expected to be 25 ppm over the 90-day study. ------- REFERENCES 1. Clarke, D. C., Baum, H., Stanley, E. L. and Hester, W. F., Anal. Chem. 23_, 1842-1844 (1951). 2. Bontoyan, W. R., Looker, L. B., Kaiser, T. E., Giang, P., and Olive, B. M., Survey of Ethylene Thiourea in Commercial Ethylene Bis Dithiocarbamate Formulations. J. Assoc. Off. Anal. Chem. _55, 923-925 (1972). 3. Engst, R. and Schnaak, W., Investigations of the Metabolism of Fungicidal Ethylene Bisdithiocarbamates Maneb and Zineb. Z. Lebensm. Unters. Forsch. 134, 216-221 (1967). 4. 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Food Chem. 20, 967-969 (1972). 11. Newsome, W. H. and Laver, G. W., Effects of Boiling on the Formation of Ethylene Thiourea in Zineb Treated Food. Bull. Environ. Contam. Toxicol. 10, 151-154 (1973). 12. Watts, R. R., Stroherr, R. W. and Onley, J. H., Effects of Cooking on Ethylene Bisdithiocarbamate Degradation to Ethylene Thiourea. Bull. Environ. Contam. Toxicol. 12, 224-228 (1974). 13. Blackwell-Smith, R., Finnegan, J. K., Larson, P. S., Sahyoun, P. F., Dreyfuss, M. L. and Haag, H. B., Toxicological Studies on Zinc and_Disodium Ethylene Bisdithiocarbamates. J. Pharmacol Exp. Ther. 109, 159-166 (1953). ------- REFERENCES (Continued) 14. Innes, J.R.M., Valerio, M., Ulland, B. M., Pallotta, A. J., Petrucelli, L., Fishbein, L., Hart, E. R., Falk, H. L., Klein, M., and Peters, A. J., Bioassay of Pesticides and Industrial Chemicals for Tumorigenicity in Mice. J. Natl. Cancer Inst. _4J2, 1101-1109 (1969). 15. Andrianova, M. M. and Alekseev, I. V., Carcinogenic Properties of the Pesticides Sevin, Maneb, Ziram and Zineb. Vopr. Pitan. 2£, 71-74 (1970). 16. Ulland, B. M., Weisburger, T. H., Weisburger, E. K., Rice, J. M., and Cypher, R., Thyroid Cancer In Rats From Ethylene Thiourea. J. Natl. Cancer Inst. ^£, 483-484 (1972). 17. Graham, S. L., Davis, K. J., Hansen, W. H., and Graham. C. H., Effects of Prolonged Ethylene Thiourea Ingestion on the Thyroid of the Rat. Fd. Cosraet. Toxicol. 13>, 493-499 (1975). 18. Jukes, T. H. and Shaffer, C. B., Antithyroid Effects of Arainotriazole. Science JL32, 296-297 (1960). 19. Purves, H, D., and Griebach, W. E., Thyroid Tumors in Rats Treated with Thiourea. Br. J. Exp. Path. 28, 46-53 (1947). 20. Freudenthal, R. I.', Kerchner, G. A.', Persing, R. L., Baumel, I., and Baron, R. L., Subacute Toxicity of Ethylene- bisisothiocyanate Sulfide in the Laboratory Rat. J. Toxicol. Environ. Health, In Press. 21. Griessen, M. and Lemarchand-Beraud, T., Thyrotropin Secretion and Metabolism in Rats during Propylthiouracil Treatment, Endocinol. ^2_, 166-173 (1973). 22. Seifter, J. and Ehrich, W. E., Goitrogenic Compounds: Pharmacological and Pathological Effects, 92, 303-314 (1948). 23. Astwood, E. B., The Chemical Nature of Compounds Which Inhibit the Function of the Thyroid Gland. J. Pharmacol. Exp. Ther. 78, 79-82 (1943). 10 ------- o o OF spm.E era. o r 0 10 20 fc MASS SPF'.n/r.MFi [n»at, or >r.. iTiiii v. eL V/ '-<;->ncfvjnf Go- ___ -jV Jg ~* Ar-p/voil Seen, .-...) f- GC A t«r; v FIGURE 1. MS ANALYSIS OF THE ETU USED AS THE TEST CHEMICAL 11 ------- UlO <£<* U.O OVj ift O _ k ""I""' CO 0 70 0O ^0 100 110 ItO 130 110 ISO ICO 170 180 190 FIGURE 2. MS OF THE ETU USED AS THE TEST CHEMICAL 12 ------- 260 250 240 230 220 210 200 190 180 O) -170 o o 160 150 140 130 120 110 100 90 80 70 60 625 ppm M T- T- A A 625 ppm Diet Consumption Amitrole A A 50 ppm M A A 50 ppm F 125 ppm M - D D 125 ppm F 25 ppm M I I I I j 1234567 Weeks on Study FIGURE 3. DIET CONSUMPTION 10 11 12 13 ------- Test Chemicgl Consumption 625 ppm M A A 625 ppm F Q Q 125 ppm M Q--r--p 125 ppm F ... - 25 ppm M 9_ £ 25 ppm F #rrr# 5 ppm M # # 5 ppm F X., X 1 ppm M -X 1 ppm F 0 ppm M Or---<> 0 ppm F Amitrole A -A 50 ppm M A -4k 50 ppm F PTU 125 ppm M 125 ppm F 45 40 35 30 25 20 | 15 10 7 8 Weeks on Study FIGURE 4. TEST CHEMICAL CONSUMPTION 14 10 11 12 ------- 500 450 400 350 » 30° '5< 250 200 150 100 Body Weight Gain O O Amitrole A A 50 ppm M A A 50 ppm F PTU 125 ppm M 125 ppm F I I 1 I I 1 1234567 Weeks on Study FIGURE 5. BODY WEIGHT GAIN 15 10 11 12 ------- TABLE 1. ETU PROTOCOL DESIGN ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole (ppm) 50 50 PTU (ppm) 125 125 Sex M F M F M F M F M F M F M F M F Number of 30 Days 20 20 20 20 20 20 20 20 20 20 24 24 20 20 20 20 Rats/Treatment Period 60 Days 20 20 20 20 20 20 20 20 20 20 24 24 20 20 20 20 90 Days 20 20 20 20 20 20 20 20 20 20 24 24 20 20 20 20 TABLE 2. TISSUES REMOVED AND WEIGHED DURING NECROPSY Heart Spleen Kidney Ovary (paired) Testicle (paired) *Liver Pituitary *Thyroid (paired) Adrenal (paired) Brain * Tissues processed for histopathologic evaluation. 16 ------- TABLE 3. THYROID HORMONE LEVELS - AFTER 30 DAYS ON STUDY ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Sex M F M F M F M F M F M F 125 I (percent uptake) 1.2 ± 2.1 ± 3.6 ± 4.0 ± 2.9 ± 3.2 ± 3.6 ± 3.8 ± 3.7 ± 3.0 ± 3.6 ± 3.5 ± * 0.4* 1.4 0.8 1.7 0.6 1.3 0.6 1.0 0.7 0.5 0.9 0.9 TBG (percent T-3 bound) 60.3 60.6 62.7 61.5 65.7 63.5 69.3 68.9 64.5 63.4 68.0 66.0 * ± 2.6* ± 1.8, ± 1.3, ± 1.3 ± 2.3 ± 2.0 ± 6.3 ± 1.3 ± 1.2 ± 1.3 ± 5.6 ± 5.2 T-3 (ng percent) 57.3 58.4 71.1 104.4 67.1 86.3 79.0 88.1 82.1 90.9 76.0 83.2 A ± 3.7* + 9.9 ±11.8* ±16.3 ±15.9 ±14.8 + 8.1 ±12.8 ±13.0 ±11.3 ±11.8 ±16.2 T-4 (ug percent) 0.9 ± 1.1 ± 2.6 ± 2.1 ± 5.6 ± 3.8 ± 4.7 ± 2.9 ± 5.1 ± 3.5 ± 5.0 ± 3.8 ± * 0.6* 1.0* 0.4 0.5* 1.1 0.8 0.4 0.9 1.0 1.0 1.7 1.4 TSH (yiu per ml) 1.4.3 14.6 23.3 18.3 7.3 5.1 6.7 4.9 6.4 4.5 6.7 6.0 * ± 0.9* ± 1-9* ± 5.9* ± 4.0 ± 1.5 ± 1.3 ± 1.4 ± 1.4 ± 0.8 ± 0.9 ± 2.5 ± 4.1 Amitrole (ppra) 50 50 PTU (ppm) 125 125 M 3.7 ± 2.1 F 5.0 ± 3.5 M 2.9 ± 1.1 F 3.3 ± 0.7 63.0 ± 1.5 61.4 ± 1.0* 67.8 ± 2.0 69.5 ± 1.6 * 49.1 + 19.5* 55. 2 ± 58. 9 ± 52. 0± 7.2 * 6.1* 8.0 0. 0. 0. 0. 6 3 9 7 ± 0 ± 0 ± 0 ± 0 * 8* .3 * 2* .1 * 9.3 ± 0.6* 8.9 ± 0.6 - Significantly different (p <0.05) from corresponding control. Student's t test was used to make comparison between the control and treated animals. All data reported as the mean, ± S.D. 17 ------- TABLE 4. THYROID HORMONE LEVELS - AFTER 60 DAYS ON STUDY ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 125 I (percent Sex M F M F M F M F M F M F uptake) 1.9 2.4 3.6 3.3 3.2 3^7 3.5 4.0 2.7 3.2 4.3 3.5 + + + + + + + + + ± + + 1.0* 1.8* 1.4 1.0 0.7 1.3 0.8 0.8 0.6 0.7 0.9 0.8 TBG (percent T-3 bound) 79.0 71.8 66.3 66,3 76.9 74.7 66.4 64.0 70.4 67.1 73.6 69.4 ± 0.9 ± 1.4 ± 1.3 ± 2.1 ± 1.6 ± 1.7 ± 1.2 ± 1.8 ± 1.2 ± 1.3 ± 4.9 ± 4.3 T-3 (ng Percent) 56.9 ± 56.8 ± 79,8 ± 78.5 ± 86.4 ± 126.2 ± 85.4 ± 118,5 ± 80.3 ± 93.3 ± 77.3 ± 103,8 ± 10.3* 6.9* 28.1 28.6* 7.6 15.1 12.7 14.3 12.0 13.5 8.5 19.1 T-4 (yg percent) 0.2 0.2 2.8 2.0 2.8 2.6 4.9 2.9 4.9 2.8 4.8 3.3 ± 0.1* ± 0.1* ± 0.5* ± 0.5* ± 0.5* ± 0.5* ± 0.5 ± 0.9 ± 0.7 ± 0.8 ± 0.7 ± 0.5 THS (yiu per ml) _ - - - - - - - - 5.8 ± 0.4** 6.4 ± 0.9** Amitrol'e (ppm) 50 50 PTU (ppm) 125 125 M F M F 4.0 4.8 3.9 5.4 ± 0.7 ± 0.9 ± 1.6 ± 1.7 74. 69, 61. 62. 8 8 7 2 ± 1.6 ± 1.3 ± 2.6* ± 2.1* 83.4 111,6 46.1 50.9 ± 8.9 ± 10.7 ± 3.9* ± 9.7* 5.9 3.5 1.2 0.8 ±0.8 ± 3.6 ± 0.2* ±6.1* - 9.8 ± 1.0* 10.8 ± 1.9* * Significantly different (p < 0.05) from corresponding control. ** TSH values to be used as control for PTU group. 18 ------- TABLE 5. THYROID HORMONE LEVELS - AFTER 90 DAYS ON STUDY ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole . (ppm) 50 50 PTU (ppm) 125 125 Sex M F M F M F M F M F M F M F M F 125 I (percent uptake) 2.5 3.7 2.8 3.9 3.3 3.4 3.7 4.2 3.5 3.2 3.8 4.1 5.8 4.8 4.7 5.6 * ± 0.8 ±: 1.8 ± 0.7 ± 1.1 ± 0.7 ± 0.9 ± 0.6 ± 1.1 ± 0.6 ± 0.9 ± 0.5 ± 1.0 ± 3.1 ± 3.2 ± 1.7 ± 2.5 TBG (percent bound) 62 62 65 64 68 65 71 70 65 63 69 65 71 69 59 60 .7 ± 2. .7 ± 0. .3 ± 1. .3 ± 1. .9 ± 1. .6 ± 2. .4 ± 0. .1 ± 2. .8 ± 1. .1 ± 1. .3 ± 2. .2 ± 2. .4 ± 1. .6 + 2. .1 ± 1. .4 ± 1. T-3 * o* 9 1 6 5 3 8 2 1 4 7 9 5 1 * 3* 7 T-3 (ng percent) 27 35 86 105 79 108 76 105 68 116 72 106 67 94 73 69 .9 ± .2 ± .1 ± .5 ± .4 ± .7 ± .1 ± .2 ± .7 ± .7 ± .0 ± .8 ± .3 ± .8 ± .2 ± .6 ± * 13.3* 4.3 15.0 16.0 12.6 11.6 13.1 16.6 9.9 17.6 21.5 25.0 11.8 13.3 9-9* 9.4 T-4 TSH (ug (uiu percent) per ml) 1.1 ± 1.1 ± 2.3 ± 1.6 ± 3.8 ± 2.9 ± 5.0 ± 3.0 ± 4.0 ± 2.5 ± 4.5 ± 3.3 ± 3.6 ± 3.5 ± 0.6 ± 0.4 ± * 0.6* 0.6* 0.6* 0.3 1.0 0.7 1.0 0.7 1.0 0-7 - . ** 0.8 5.8 ± 0.4** 0.8 6.4 ± 0.9 1.3 1.1 * * 0.2* 9.4 ± 1.3* 0.2 10.7 ± 2.1 Significantly different (p < 0.05) from corresponding control. ** TSH values to be used as control for PTU group. 19 ------- TABLE 6. FREE THYROXINE INDEX -. . . - ETU (ppm) 625 625 125. 125 25 25! 5 5 1 1 6 0 Ami;tr,ple 5Q- 50-, PTU (ppm) 125 125' Sex M F M F M F M F M- F M F U| F, M F' Days 30 0.5,2 0.67 1.6.2 1.27 3.69; 2, 42* 3.24, 2'. OP. 3 ."28. 2.22 3 . 3.7 2.52. Q>3& 0.15, 0.64. 0.49- on Study 6Q Q.15 0.12 1,86 1.35 2'..12 1.9;i 3:.2-7- 1 ..88; 3.,49 1.86> 3'.52' 2...31: 4, 37 2 .42 0, 74, 0,48; :90 0.68 0.70 1.4,8 1,0.5 2. .64 1 . 9,0. 3.. 5.3: 2.12 2.64. 1.52: 3j. 12 2. .14 2.53 2.. 41 0.33', 0,23 20 ------- TABLE 7. WEEKLY DIET CONSUMPTION ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole (ppm) 50 50 PTU (ppm) 125 125 Sex M F M F M F M F M F M F M F M F Week No. 1 91.2 + 14.1 85.0 + 14.9 120.3 + 27.0 105.8 + 33.5 114.7 + 27.0 95.0 + 20.8 136.2 + 18.9 121.6 -1- 24.8 137.0 + 18.0 112.3 + 13.6 145.5 + 35.2 123.3 + 43.3 138.4 + 16.4 114.0 + 19.2 150.6 + 17.7 120.7 + 13.8 Week No. 2 114.6 + 29.5 103.8 + 30.7 141.9 + 19.5 107.7 + 18,7 153.6 + 17.0 119.8 + 22.9 155.4 + 20.5 115.4 + 23.2 143.5 + 26.0 116.5 + 23.2 151.1 + 20.4 119.1 + 22.8 146.1 + 17.6 118.8 + 20.8 136.7 + 17.5 108.6 +16.6 Week No. 3 102.0 + 14.8 83.9 + 24.3 152.7 + 20.6 115.8 + 22.9 165.3 + 23.6 129.8 + 37.9 167.9 + 26.8 123.1 + 19.9 171.1 + 28.1 123.1 + 27.9 169.9 + 21.5 131.7 + 43.2 162.3 + 19.8 127.3 + 31.7 113.6 + 23.4 95.5 + 23.7 Week No. 4 100.7 + 16.3 84.0 + 17.2 150.6 + 27.3 126.8 + 42.2 166.6 + 18.7 127.1 + 27.6 171.2 + 36.1 129.3 + 38.7 173.9 + 41.5 121.2 + 29.3 168.0 + 20.3 131.6 + 39.1 165.6 + 19.9 133.3 + 32.9 100.1 + 17.2 74.4 + 13.3 Week No. 5 98.5 + 17.2 82.2 + 24.1 171.3 + 35.2 136.8 + 58.3 169.2 + 13.6 116.6 + 17.5 169.0 + 21.1 128.7 + 29.3 168.8 + 13.4 120.9 + 23.3 176.7 -1- 35.0 140.9 + 39.7 175.8 + 26.0 130.2 + 26.9 104.1 + 14.5 86.7 + 27.6 Week No. 6 101.0 + 20.8 85.2 + 23.9 159.6 + 22.1 124.5 + 31.4 172.1 + 24.9 121.1 + 25.1 174.3 + 19.8 128.8 + 20.7 179.0 + 27.3 140.3 + 43.4 182.9 + 47.7 146.3 + 59.2 169.9 + 30.9 127.1 + 26.8 96.8 + 18.7 89.1 + 21.2 ------- TABLE 7. (Continued) ro ts) ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole (ppm) 50 50 PTU (ppm) 125 125 Sex M F M F M F M F M F M F M F M F Week No. 7 107.8 + 17.9 92.6 + 24.8 165.0 + 13.7 114.7 + 11.9 188.7 + 43.9 138.3 + 32.9 173.6 + 27.7 125.2 + 26.9 181.9 + 45.9 144.6 + 53.2 191.6 + 48.7 146.8 + 48.7 177.6 + 40.8 138.0 + 51.6 102.7 + 19.0 95.5 ± 19.5 Week No. 8 117.9 +15.3 105.2 + 20.8 178.2 + 43.2 120.5 +21.2 183.5 + 23.1 139.0 + 43.3 181.0 + 37.4 133.9 + 51.9 182.9 + 33.2 131.9 + 34.3 181.8 + 48.7 146.6 + 55.8 182.1 + 38.0 132.9 +48.4 96.4 + 18.9 91.3 + 28.1 Week No. 9 117/8 + 20.7 106.1 +27.1 167.6 +38.4 163.1 + 83.1 195.3 + 34.4 143.3 + 36.9 173.2 + 31.2 130,7 + 25.4 182.7 + 27.9 146.0 + 46.7 177.8 + 30.5 138.1 + 36.2 185.9 + 39.9 129.2 + 40.8 91.0 + 19.4 96.5 + 28.3 Week No. 10 121.0 + 20.1 101.8 + 20.8 176.7 +29.5 146.6 + 54.8 176.8 + 16.3 133.0 + 26.1 158.6 + 35.3 127.6 + 47.0 207.8 + 56.2 145.8 + 49.1 186.5 + 40.4 153.2 + 66.6 229.1 + 75.6 174.6 + 79.8 101.9 + 16.5 89.1 + 20.8 Week No. 11 114.8 + 17.2 93.8 + 13.5 181.2 + 46.8 137.1 + 50.9 198.2 + 51.7 151.4 + 63.1 172.9 + 38.3 129.7 +24.3 207.9 + 54.2 148.1 +61.5 183.4 + 45.0 149.0 + 66.8 165.8 + 22.0 118.4 + 25.7 91.5 +18.1 68.5 + 9.9 Week No. 12 91.6 + 18.7 89.8 + 30.2 164.3 + 27.9 129.6 + 56.9 200.7 + 59.8 170.0 + 69.4 154.2 + 18.0 111.1 + 16.5 168.8 + 18.0 109.6 + 14.9 177.8 + 46.2 131.7 +50.9 192.5 + 32.1 138.1 + 59.0 92.0 + 14.1 88.2 + 15.4 Mean, + S.D.; presented in grams, ------- TABLE 8. WEEKLY TEST CHEMICAL INGESTION* ro OJ ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole (ppm) 50 50 PTU (ppm) 125 125 Sex M F M F M F M F M F M F M F M F Week No. 1 57.0 53.1 15.0 13.2 2.9 2.4 0.7 0.6 0.1 0.1 0 0 6.9 5.7 18.8 15.1 Week No. 2 71.6 64.9 17.7 13.5 3.8 3.0 0.8 0.6 0.1 0.1 0 0 7.3 5.9 17.1 13.6 Week No. 3 63.7 52.4 19.1 14.5 4.1 3.3 0.8 0.6 0.2 0.1 0 0 8.1 6.4 14.2 11.9 Week No. 4 62.9 52.5 18.8 15.9 4.2 3.2 0.9 0.7 0.2 0.1 0 0 8.3 6.7 12.5 9.3 Week No. 5 61.6 51.4 21.4 17.1 4.2 2.9 0.9 0.6 0.2 0.1 0 0 8.8 6.5 13.0 10.8 Week No. 6 63.1 53.3 19.9 15.6 4.3 3.0 0.9 0.6 0.2 0.1 0 0 8.5 6.4 12.1 11.1 Week No. 7 67.4 57.9 20.6 14.3 4.7 3.5 0.9 0.6 0.2 0.1 0 0 8.9 6.9 12.8 11.9 Week No. 8 73.7 65.7 22.3 15.1 4.6 3.5 0.9 0.7 0.2 0.1 0 0 9.1 6.7 12.1 11.4 Week No. 9 73.6 66.3 21.0 20.4 4.9 3.6 0.9 0.7 0.2 0.2 0 0 9.3 6.5 11.4 12.1 Week No. 10 75.6 63.6 22.1 18.3 4.4 3.3 0.8 0.6 0.2 0.2 0 0 11.5 8.7 12.7 11.1 Week No. 11 71.7 58.6 22.7 17.1 5.0 3.8 0.9 0.7 0.2 0.2 0 0 8.3 5.9 11.4 8.6 Week No. 12 57.3 56.1 20.5 16.2 5.0 4.3 0.8 0.6 0.2 0.1 0 0 9.6 6.9 11.5 11.0 Mean, + S. D.; presented in grams. ------- TABLE 9. WEEKLY BODY WEIGHT GAIN to Weeks on Study ETU, ppm 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole 50 50 PTU 125 125 Sex M F M F M F M F M F M F M F M F 0 129.4 ± 14.2 117.5 ± 12.0 132.1 ± 17.5 116.61 14.6 145. 0± 11.3 127.2 ± 12.1 140.5 ± 13.9 124. 0± 12.4 131. 0± 16.6 115.2 ± 13.7 141. 0± 27.6 119. 0± 21.1 139.1± 18.7 120.21 13.7 168.5+ 39.8; 136.41 26.6 1 141.4 H5.0 127.2 ±12.6 180.3 ±22.7 146.3 ±13.1 188.6 ±18.1 152.1 ±13.3 195.3 1 14.4 155.1 ±11.4 191.5 ± 22.1 151.6 1 13.9 193.8 1 29.4 151.61 18.0 199.51 20.8 155.51 16.2 224.31 35.2 167.81 22.5 2 157.7 117.8 135.5 112.6 226.7 ±24.4 168.2 ±15.1 242.1 115.2 176.5 +14.8 248.9 ± 21.5 179.4 ±23.9 234.01 29.9 173.4 1 14.7 242.81 30.1 174.91 22.2 245.31 25.7 176.71 19.0 241.91 37.0 174.11 24.3 3 172.ll 24.3 143.61 15.8 274.01 27.0 188.91 16.0 295.01 20.0 199.71 16.8 299.81 22.9 201.61 19.6 292.71 32.7 193.81 17.3 290.5 +36.9 194.5 ±21.5 291.5 + 27.5 195.1 ±23.7 245.3 + 34.9 176.3 ± 25.8 4 187.2 ± 25.3 148.6 ±17.5 306.6 ±37.3 204.1 ± 20.8 335.9 ±21.9 217.4 ±.18.4 340.1 ± 28.8 218.2 ± 21.5 332.3 1 35.2 213.31 20.2 331. 9± 35.8 211.01 20.1 328.61 27.2 216.51 21.6 247. 4± 32.1 178. 1± 24.2 5 195.1 ±21.1 152.6 116.2 341.3 ±38.2 217.3 ±25.8 376.9 ±22.9 228.8 ± 20.6 373.9 ± 30.4 238.5 ± 22.8 377. 5± 37.6 227.4± 17.8 366.4+ 35.3 228.9+ 21.6 361.6+ 30.5 232.6+ 24.8 261. 7± 30.2 183. 5±. 26. 9 6 189.6 ±26.5 145.7 ±21.5 365.7 ±38.0 230.7 ±23.0 401.3 ± 21.3 241.0 ± 23.8 398.5 ± 36.3 254.1 ± 22.0 408. 6± 40.9 238. 1± 18.4 394.5+ 33.6 242.3±;23.7 378. 3± 37.5' 243.4+ 23.9 265.0+ 29.3 185.0+ 26.7 ------- TABLE 9. (Continued) ETU, ppm 625 625 125 125 25 25 5 5 1 1 0 0 Amitrole 50 50 PTU 125 125 Sex M F M F M F M F M F M F M F M F 7 195.7 ±36.0 148.8 ± 25.0 385. 3± 40.5 242. 1± 23.4 420. 1± 29.0 250. 9± 22.9 425.1+ 39.4 263. 3± 24.1 428. 6 ± 44.4 249. 1± 19.6 417. 9± 36.0 251. 1± 22.0 407. 4± 37.0 249. 8± 22.7 265. 5± 30.4 184. 9 ± 27.5 8 210.7 ± 34.6 161.9 ± 21.6 413.4 ±32.3 249. 9± 26.6 443.0+ 26.0 254.3 + 25.6 447. 8± 42.2 269. 6± 25.4 446.7+ 49.7 256.5+ 19.1 432.9+ 39.7 263. 3± 30.6 428. 8± 44.2 258.2+ 25.8 265.7+ 31.0 183.71 27.8 Weeks on 9 234.8 ±29.8 170.3 +25.7 431.4 ±36.7 250.8 ±22.0 451.9 +29.2 273.6 +25.0 457.7 +38.4 274.9 +26.5 442.0 ±49.0 260,0 ±20.8 448.9 ±35.7 266.6 +30.5 437.5 ±44.4 254.9 ±32.8 259.0 ±33.0 171.8 ±28,0 Study 10 246.6 ±34.8 180.7 ±23.1 444.6 +40.2 254.5 +25.5 466.4 ±26.1 275.2 ±23.1 468.7 ±35.4 286.7 +25.8 462.0 ±49.4 267.5 ±20.1 461.1 ±38.8 275.2 ±26.6 456.4 ±40.1 263.8 ±31.2 259,3 + 35,5' 171,1 +28.9 11 25.1.2 ±38.2 181.3 ±23.9 462.5 ±40.9 265.7 ±24.4 483.5 ±33.1 283.3 +23.3 478.8 ±38.5 290.2 ±23.4 476.0 ±52.9 269.8 ±24.0 478.4 ±33.7 280.5 +28.0 471.1 ±40.0 269.0 ±32.2 265,3 + 35,7 172.4 +27,6 12 239.4 ±40.3 171.5 ± 28.3 472.1 ±43.3 268.1 ±23.4 497.5 ±33.8 288.8 ±26.9 491.9 ± 39.2 295.2 ±26.8 492.3 ± 55.3 276.3 ± 22.2 492. 1± 35.2 285.9 ± 30.7 487.7 ± 40.4 275.5 ± 32.6 265, 6 ± 37.2 174,5 ± 29.0 * Mean, + S.D.; presented in grams. ------- TABLE 10. OKCAN WKICHTS DB'iAINEU AT NKCROFSY F.TU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 "' 25 5 5 1 0 0 625 62'. 125 25 25 r( 1 1 0 0 Days on Study 90 90 90 90 90 90 90 90 90 90 90 90 60 60 60 60 60 60 60 60 60 60 60 60 10 10 1(1 to 11) 10 10 10 30 10 10 30 Heart S>>x (K) M F M F M F M F M F M F M F M F M F M F M F M F M j,. M F M F M F M F M P 0.77 0.58 1.37 (1.88 1.41 0.97 1 .41 0.40 1 . 39 0.84 1.41 0.91 0.77 0.57 1.37 0.95 1.38 0.8.S 1.43 0.92 1.29 0.81 1.15 0.90 0.61 0. >:> 1 .(IS (1.8 t 1.1'. O.K.' 1 . I 1 0.77 1.16 0.74 1.2) 0.86 ' 0 . 1 ft 1 0. 1 1 ' 0.1) 1 0.07 .1 1) . 1 4 1 I). 11 ' 0.22 ' 0.09 i 0. 15 ! 0.06 . 0.19 '. 0.09 + 0.31 ±0.06 ± 0.23 ± 0.33 i 0.09 ± 0.1 1 ± 0.18 i 0.13 < 0.16 ± 0. 10 1 0.21 ' 0.09 i 0.08 i 0.118 i 0.09 i (1.08 i (1.12 . 0.07 i 0.09 . 0. 10 . 0. 12 1 0.05 i 0.26 ' 0. 17 Si .1.28 0.24 0.81 0.51 0.84 0.5) (1.88 0.54 0.80 0.52 0.90 0.55 0.31 0.21 0.76 0.54 0.80 0.51 (1.84 0.54 0.72 0.55 0.74 0.56 ll.:)4 (1. 28 II.7/. 11.51 11.79 (1.54 11.79 II. 52 0.72 0.51 0.77 0.51 1 fun (s) i 0.11 ' 0.07 ' 0.11 ' 0.12 > 0.12 ' 0.09 1 I). 1 1 ' 0.09 ! 0.15 i 0.09 L 0.10 1 0.11 ± 0.19 ± 0.03 ± 0.13 ± 0.08 ±0.10 ±0.04 i 0.10 ±0.07 ± 0.09 ±0.07 i 0.12 ± 0.10 1 1.07 . 1.06 . I. 1 1.64 .1.11 i 1. Ill i 1.08 . 1.06 t II. 11 t 11.08 ±0.10 ±0.06 Rt . Kidney 0.85 0.65 1.69 0.91 . 59 .00 .49 .00 .55 0.94 1.62 1.01 0.86 0.67 1.46 0.94 1.64 0.99 1.65 0.96 1.55 0.99 1 .64 1 .05 11.10 0.64 1 . 26 0.40 1 .29 0.92 1 .13 0.81 1.26 0.81 1.39 0.85 ' 0. 1 1 ' O.Od ' 0.29 ' 0.10 1 0. 17 ' II. Ill ' 0.19 ' 0.09 ' 0.22 1 0.08 ! 0.20 '. 0. 1.1 i 0.19 1 0.03 i 0.08 i 0.06 1 0.21 i 0.14 '. 0.21 .' 0.07 ' 0.19 1 0. 17 ' 0.25 ' 0.26 ' 11. 1 2 ' (1.09 1 0.09 1 0.09 ' 0.119 ' 0.119 1 0.15 ' 0.09 1 0.08 ' 0.05 ' 0.18 1 0.07 l.oft Kidney II. SI i 0.1.1 ' 1.6'. . 0.92 i 1.61 . 0.98 i 1.44 i 0.97 i 1 .55 i 11.94 i 1 . 60 . 0.97 i 0.88 ± 0.65 ± 1.45 ± 0.91 ± 1.63 i 0.99 + 1.59 i 0.91 i 1.57 ... 0.94 i 1.62 .. 0.94 i 11.79 i 11.65 ' 1.2'. i 11.86 ' 1 .28 i 0.91 ' 1.1'. ' 0.82 i 1 .24 i 0.81 .' 1 . 18 i 0.85 .' 0.14 II.O5 0.11 0.08 0. 17 (1. 1 1 1). 18 II. 10 0.22 0.09 0.18 0.10 0.21 0.01 0.11 0.08 0.21 0.12 0.22 0.09 0.18 0.09 0.22 0.15 0. 12 0. Ill O.ll'l 0. 10 0.07 (1.09 0. 11 0.08 0.08 0.06 0. 19 0.09 Ovary (pal rod; K) (1.08 11.09 I). 1(1 0. 1 1 0. 10 0.10 0.08 0.13 0.10 0.10 0.10 0. 12 0.09 0. 12 0. 12 0. 1 1 0.12 0.12 1 0.02 ' 0.-02 ' 0. 14 1 0.01 ! 0.02 ± 0.02 ± 0.02 ' 0.01 '. 0.02 1 0.02 1 0.02 ' 0.01 1 0.01 ' 0.02 1 0.02 1 0.01 1 0.02 ': 0.02 Tos (pal 4.37 5.17 5.11 5 . 29 5.11 5.67 3.17 4.59 5.35 5.04 4.99 4.90 1.8 ) 4 . 08 4.21 4.13 3 .16 4 . 23 tide ri-d; K) i 0 ' 0 i 0 < 0 .' 0 ± 0 ± 1 + 0 60 V. 71 55 10 55 14 51 ' 0.53 ± 0 ± 0 . 0 1 0 i () 1 () 60 55 72 16 ''4 4 5 i [),27 . g f o 41 47 7 (, 19 9 17 10 16 10 17 10 17 10 8 7 17 10 20 10 17 111 16 9 J7 10 8 7 1 .5 14 4 16 8 14 Q 15 9 Liver (R) 5d 51 06 78 62 92 62 72 98 57 33 21 00 57 42 12 82 32 86 53 69 49 21 11 16 92 72 44 88 7f, 08 83 18 64 24 92 i 1 . 0 1 -J < I) 1 1 1 1 i 2. 1 i 1 < 1 . 1 . 1 i 1 ± o ± 1 ± 1 ± 3 t 1 i 1 . .1 i 2 54 8 t 40 99 91 01 14 67 04 28 92 22 13 66 37 31 22 55 09 03 10 i 0.96 i 2 ' 2 1 0 i . 1 0 1 1 1 0 1 2 1 1 1 0 i 1 58 24 88 2'. 15 95 I | 72 4 1 I 3 31 97 21 29 Pituit (mtf 10 11 10 1 2 10 10 25 80 80 38 ary ) ! 1 4 i 2 1 2 '- 2 1470 ! 2 1 1 14 9 .11 11 14 10 9 13 12 10 8 8 11 9 12 10 16 12 7 10 10 8 8 8 a 7 7 9 11 (10 20 80 90 42 83 20 11 70 10 40 80 60 20 20 40 08 75 10 10 40 60 70 40 90 20 70 70 58 50 ' 3 1 3 ! 4 * 4 i 3 i 6 i 3 i 2 ± 2 ± 2 ± 1 ± 3 t 2 i 2 1 1 3 ' 3 '- 6 1 ) 1 2 , 2 , 3 , 2 , 1 + 2 7.5 ^ 3 Thvrold ('««) 6 1 40 10 94 33 75 27 68 37 15 09 44 11 12 79 18 58 08 07 30 99 81 61 82 64 78 72 77 86 45 1 5 89 58 91 06 48 45 17 J. I 24 20 2'i 18 27 2 ' .in < ' 57 38 37 27 14 23 20 18 27 21 29 21 29 28 11 23 26 2.1 20 16 19 14 24 16 JO !!S .11 71 51 21 71 91 51 II 42 00 60 11 10 30 50 00 40 to 00 80 17 25 10 80 20 80 00 90 to 50 40 80 17 00 ' 24 ' 12 ' 8 1 ' 9 ' 6 ' 4 6 ' 4 ' 4 ' 8 ' 4 ' 19 ' 18 ± 10 ± 7 ± 7 '- 5 i 4 i 4 ± 6 i 6 i 13 i 9 i 8 '. 6 1 12 '. 7 i 6 .': 4 .' 4 1 3 -' 3 1 2 ± 8 i 3 34 98 21 53 88 05 97 06 77 47 64 45 09 40 93 01 37 79 40 12 38 14 72 66 04 84 70 24 62 38 04 66 24 90 13 52 Adrona 1 (paired; m>>) 40. 43. 48. 52 51 59 48 61 49 64 51 66 41 41 55 63 48 59 47 63 50 57 52 65 38 37 45 58 48 61 49 55 45 61 45 57 70 13 20 10 30 60 90 60 80 40 13 08 40 00 90 00 50 40 60 40 00 10 25 00 00 20 40 20 40 30 70 50 30 30 50 75 '6.15 1 8.64 1 10,02 ' 7.80 ' 8.18 '- 8.1.9 i- 9.40 ' 8.51 1 7. 11 ' 10.27 i 6.10 ±11.85 ± 11.02 ± 7.48 1 9.64 ± 10.74 ± 6.17 ± 1.5.28 ± 9.08 ± 8.06 ± 8.99 1 14.91 ± 9.96 ± 14.57 ± 7.60 ± 8.01. '. 6.82 1 9 . 00 -' 11.61 J 6.62 ± 8.72 i 5.87 i 7 . 66 ± 11.56 i 6.57 ± 6.21 Brain (g) 1.80 ± 1.66 1 2.05 ± 1.81 ± 2.06 i 1.90 ± 2.05 ± 1.89 ± 2.04 ± 1.80 ± 2.08 ± 1.81 ' 1.76 1.65 2.00 1.85 2.04 1.88 1.95 1.88 1.99 1.84 2.06 1.'90 .1.71 1.68 1.88 1.78 1.88 1.79 1.97 1.76 1.92 1.79 1.91 1.81 0.08 0.08 0.14 0.09 0.06 0.08 0.12 0.81 0.13 0.18 0.09 0.10 t 0.07 ± 0.10 ± 0.13 ± 0.11 ± 0.07 ± 0.07 ± 0.15 ± 0.10 ± 0.14 ± 0.13 ± 0.13 ± 0.07 ± 0.11 ± 0.09 ± 0.07 ± 0.07 ± 0.09 ± 0.07 i 0.12 ± 0.07 ± 0.11 ± 0.06 ± 0.08 ± 0.08 ------- TABLE 10. (Continued) Ami t role (ppm) 50 50 50 50 50 50 PTU (ppm) 125 125 125 125 125 125 Control (ppm) 0 0 0 0 0 0 Days on Study 90 90 60 60 30 30 90 90 60 60 30 30 90 90 60 60 30 30 Sex M F M F M F M F M F M F M F M F M F Heart (K) 1.29 0.89 1.27 0.92 0.89 0.72 0.71 0.54 0.73 0.62 0.60 0.52 1.43 0.93 1.35 0.90 1.23 0.86 * 0.15 k- 0.09 1 0.21 1 0.12 1 0.07 f 0.11 1 0.11 k 0.07 i 0-09 ± 0.12 ± C OS ± 0.07 t 0.19 t 0.09 1 0.21 k 0.09 1 0.2(. 1 0.17 Spleen 0.80 0.61 0.75 0.57 0.55 0.54 0.25 0.20 0.35 0.28 0.31 0.25 0.90 0.55 0.74 0.56 0.77 0.53 + 0.11 1 0.09 ^ 0.08 1 0.06 1 0.06 1 0.11 1 0.05 > 0.03 k 0.07 * 0.05 ± 0.05 ± 0.04 < o.io < 0.11 < 0.12 1 0.10 1 0.12 t 0.06 Rt. Kidney 1.49 1.01 1.58 1.01 1.09 0.80 0.77 0.60 0.94 0.69 0.78 0.61 1.62 1.01 1.64 1 .05 1.39 0.88 f 0.20 ! 0. II 1 0.21 1 0.08 t 0.08 1 0.06 1 0.06 1 0.10 t 0.10 t 0.06 ± 0.10 t 0.07 J- 0.20 1 0.11 t 0.25 1 0.26 1 0.18 1 0.07 Left Kidney Ovary Testicle (g) (paired; g) (paired; g) 1 .51 1.00 1.56 0.99 1.11 0.80 0.76 0.59 0.94 0.70 0.77 0.59 1.62 0.97 1.62 0.94 1.38 0.85 k- 0. 1 0. 1 0. 1 0. 1 0. 1 0. 1 0. k 0. t 0. ± 0. ± 0. * 0. 0. 0. 0. 0. 0. 0. 19 -- 5.15 ± 0.45 11 0. 10 1 0.01 20 5.02 <" 0.54 11 0.10 1 0.02 08 -- 4.10 * 0.43 06 0.13 k 0.03 07 -- 4.47 l 0.34 1 1 0.07 ± 0.01 11 -- 4.84 -k- 0.62 09 0.09 t 0.02 09 -- 3.86 ± 0.18 05 0.09 ± 0.02 18 -- 5.67 + 0.55 10 0.10 * 0.02 22 4.90 ± 0.72 15 0.12 1 0.03 19 -- 4.23 > 0.47 09 0.12 t 0.02 17. 10. 17. 10. 13. 10. 8. 6. 9. 7. 8. 6. Liver 25 '' 48 1 33 k 53 t 73 » 70 ' 39 ± 53 t 54 k 48 ± 01 ± 92 t 1 7. 33 k- 10. 17. 10. 15. 9. 21 k 23 1 33 * 24 ' 92 ' 2.70 0.76 2.79 1.27 2.30 1.85 0.89 1.19 1.31 0.97 1.40 0.84 1.92 1.22 2.58 2.24 1.21 l.l!9 Pituitarv (mg) 12.44 t 17.30 k 10.40 k 14.60 k 7.80 i 7.60 * 8.11 i 9.90 ± 7.90 ± 8.90 ± 7.30 ± 7.20 ± 11.42 ± 14.83 k 10.08 * 16.75 k- 9 . 58 > 11.50 t 2.40 5.00 2.67 4.99 2.90 1.78 3.02 2.47 2.02 3.25 3.86 2.70 3.09 6.44 3.63 6.62 5.93 3.06 Thyroid (paired; mg) 64 41 36 24 71 53 113 86 101 90 55. 62, 30, 25. 29. 23. 24, 16. .80 k .60 1 .30 k .30 1 .90 1 .80 1 .40 ± .10 ± .80 ± .20 =k .60 ± .20 ± ,42 t ,00 t .17 I .25 k .17 k ,00 k 15.34 9.77 11.27 6.18 12.31 9.20 44.90 31.56 33.68 26.64 12.77 17.94 8.64 4.45 13.72 9.66 8.13 3.52 Adrenal (paired; mg) 48. 61. 44. 67. 35. 52. 28. 26. 28. 34. 23. 27. 51. 66. 52. 65. 45. 57. 10 t 10 t 80 * 20 I 60 k 80 I 67 ± 60 ± 70 ± 20 ± 50 ± 70 ± 33 t 08 + 20 t 00 (- 50 k 75 + 8.35 7.20 7.22 10.59 8.02 7.90 6.67 3.63 5.96 5.41 2.07 5.72 6.30 11.85 9.96 14.57 6.57 6.21 Brain (g) 2.01 + 1.90 k 2.03 * 1.87 t 1.89 t 1.72 t 1.85 ± 1.77 ± 1.92 t 1.80 ± 1.80 ± 1.71 ± 2.08 ± 1.83 ± 2.06 ± 1.90 * 1.91 ± 1.81 t 0.08 0.05 0.15 0.05 0.07 0.04 0.13 0.11 0.13 0.11 0.08 0.05 0.09 0.10 0.13 0.07 0.08 0.08 ------- TABLE 11. ORGAN WEIGHT:BODY WEIGHT RATIO ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 Days on Study 90 90 90 90 90 90 90 90 90 90 90 90 60 60 60 60 60 60 60 60 60 60 60 60 30 30 30 30 30 30 30 00 30 30 30 30 Sex M F M F M F M F M F M F M F M F M F M F . M F M F M F M F M F M F M F M F Heart (g) 3.63 x 10"3 3.A4 x 10~3 2.82 x 10~3 3.25 x 10~3 2.78 x 10~3 3.29 x 10~3 2.85 x 10~3 3.13 x 10~3 2.73 x 10~3 -3 2.99 x 10 -3 2.72 x 10 -3 3.28 x 10 3.79 x 10~3 3.68 x 10~3 -3 3.29 x 10 -3 3.76 x 10 -3 2.94 x 10 3.46 x 10~3 -3 3.05 x 10 -3 3.43 x 10 -3 2.79 x 10 3.19 x 10~3 2.97 x 10~3 3.33 x 10~3 3.28 x 10~3 3.39 x 10~3 _3 3.24 x 10 3.87 x 10~3 -3 3.43 x 10 _3 3.72 x 10 -3 3.18 x 10 -3 3.71 x 10 3.58 x 10~3 -3 3.52 x 10 -3 3.39 x 10 3.84 x 10~3 Spleen (g) 1.34 x 10~3 1.41 x 10~3 1.70 x 10~3 1.93 x 10~3 1.66 x 10~3 1.79 x 10~3 1.78 x 10~3 1.85 x 10~3 1.56 x 10~3 -3 1.84 x 10 -3 1.71 x 10 -3 1.95 x 10 1.53 x 10~3 1.35 x 10~3 -3 1.81 x 10 -3 2.13 x 10 -3 1.70 x 10 2.09 x 10~3 -3 1.79 x 10 -3 2.02 x 10 -3 1.56 x 10 2.12 x 10~3 1.63 x 10~3 2.07 x 10~3 1.80 x 10~3 1.81 x 10~3 -3 2./-S x 10 2.39 x 10~3 -3 2.35 x 10 -3 2.44 x 10 -3 2.27 x 10 -3 2.51 x 10 2.24 x 10~3 -3 2.41 x 10 -3 2.12 x 10 2.38 x 10~3 Rt. Kidney Ovary (g) (paired, g) 3.99 x 10~3 3.81 x 10~3 4.60 x 10~4 3.41 x 10~3 3.41 x 10~3 3.43 x 10~4 3.12 x 10~3 3.42 x 10~3 3.31 x 10~4 3.01 x 10~3 3.48 x 10"3 3.71 x 10~4 3.04 x 10~3 -3 -4 3.34 x 10 3.70 x 10 -3 3.09 x 10 -3 -4 3.56 x 10 3.56 x 10 4.26 x 10~3 4.34 x 10~3 5.25 x 10~4 -3 3.51 x 10 -3 -4 3.75 x 10 5.21 x 10 -3 3.50 x 10. 3.92 x 10~3 3.80 x 10~A -3 3.51 x 10 -3 -4 3.57 x 10 3.85 x 10 -3 3.37 x 10 3.78 x 10~3 3.99 x 10~4 3.60 x 10~3 3.87 x 10~3 4.40 x 10~4 4.29 x 10~3 4.21 x 10~3 5.79 x 10~4 -3 3.89 x 10 4.20 x 10~3 5.44 x 10~4 -3 3.84 x 10 -3 -4 4.14 x 10 5.33 x 10 -3 3.82 x 10 _3 -/, 3.9/ x 10 5.38 x 10 3.89 x 10~3 -3 -4 3.85 x 10 5.82 x 10 -3 3.84 x 10 3.77 x 10~3 5.40 x 10~4 Testicle (paired, g) 2.07 x 10~2 1.06 x 10~2 __ 1.05 x 10~2 1.07 x 10~2 __ 1.01 x 10~2 -2 1.08 x 10 2.06 x 10"2 -2 1.10 x 10 -2 1.14 x 10 -2 1.88 x 10 -2 1.09 x 10 _ 1.08 x 10"2 2.06 x 10~2 -2 1.26 x 10 _2 1.26 x 10 _2 1.24 x 10 1.23 x 10"2 -2 1.17 x 10 28 ------- TABLE 11. (Continued) ETU (ppm) 625 625 125 125 25 25 5 5 1 1. 0 0 625 625 125 125 25 25 5 5 1 1 0 0 525 625 125 125 25 25 5 5 1 1 0 0 Days on Study 90 90 90 90 90 90 90 90 90 90 90 90 60 60 60 60 60 60 60 60 60 60 60 60 30 30 30 30 30 30 30 30 30 30 30 30 Sex M F M F M F M F M F M F M F M - F M F M F M F M F M F M F M F M F M F M F Liver (8) 3.59 x 10"2 3.84 x 10"2 3.91 x 10"2 3.59 x 10"2 3.46 x 10"2 3.72 x 10"2 3.37 x 10"2 3.72 x 10"2 3.54 x 10"2 3.76 x 10"2 3.31 x 10~2 3.60 x 10"2 3.91 x 10"2 4.91 x 10"2 4.17 x 10"2 4.03 x 10"2 4.44 x 10"2 4.05 x 10"2 3.80 x 10"2 3.93 x 10"2 3.63 x 10"2 3.64 x 10"2 3.79 x 10~2 3.82 x 10"2 4.50 x 10~2 5.21 x 10"2 4.84 x 10"2 4.43 x 10"2 4.42 x 10~2 4.40 x 10"2 4.62 x 10"2 4.24 x 10"2 4.40 x 10"2 4.02 x 10"2 4.22 x 10"2 4.43 x 10"2 Pituitary (g) 4.79 x 10"5 7.82 x 10"5 2.22 x 10~5 4.71 x 10"5 2.04 x 10"5 5.01 x 10"5 2.23 x 10"5 4.92 x 10*5 1.93 x 10"5 4.94 x 10"5 2.18 x 10"5 5.23 x 10"5 5.03 x 10"5 5.90 x 10"5 3.28 x 10"5 4.81 x 10"5 2.22 x 10"5 3.45 x 10"5 1.84 x 10"5 4.18 x 10"5 2.00 x 10"5 4.75 x 10"5 2.22 x 10~5 6.19 x 10"5 6.82 x 10"5 4.80 x 10"5 3.20 x 10"5 4.97 x 10"5 2.58 x 10"5 3.79 x 10"5 2.55 x 10"5 3.94 x 10"5 2.39 x 10"5 3.67 x 10"5 2.65 x 10"5 5.13 x 10"5 Thyroid (paired; g) 22.91 x 10"5 27.10 x 10"5 7.66 x 10"5 8.73 x 10~5 5.80 x 10~5 6.88 x 10"5 5.21 x 10"5 6.55 x 10"5 5.41 x 10"5 7.14 x 10"5 5.80 x 10"5 8.81 x 10"5 5.03 x 10"5 5.90 x 10"5 3.28 x 10"5 4.81 x 10"5 2.22 x 10"5 3.45 x 10"5 1.84 x 10"5 4.18 x 10"5 2.00 x 10"5 4.75 x 10"5 2.22 x 10"5 4.19 x 10"5 15.82 x 10"5 18.90 x 10~5 10.20 x 10"5 11.20 x 10"5 7.72 x 10"5 9.89 x 10"5 5.77 x 10"5 7.93 x 10"5 6.02 x 10"5 7.06 x 10"5 6.20 x 10"5 7.14 x 10"5 Adrenal (mg) 1.93 x 10~4 2.54 x 10~4 0.99 x 10"4 1.92 x 10"4 1.01 x 10"4 2.03 x 10"4 0.99 x 10"4 2.20 x 10"4 0.98 x 10"4 2.29 x 10"4 0.98 x 10"4 2.33 x 10"4 2.04 x 10"4 2.66 x 10"4 1.34 x 10"4 2.51 x 10"4 1.03 x 10"4 2.33 x 10"4 1.02 x 10"4 2.37 x 10"4 1.09 x 10"4 2.19 x 10"4 1.15 x 10"4 2.40 x 10"4 2.05 x 10"4 2.45 x 10"4 1.40 x 10"4 2.73 x 10"4 1.44 x 10"4 2.70 x 10"4 1.43 x 10"4 2.67 x 10"4 1.40 x 10"4 2.92 x 10"4 1.26 x 10"4 2.58 x 10"4 Brain (8) 8.53 x 10~3 9.79 x 10"3 4.21 x 10"3 6.66 x 10"3 4.04 x 10"3 6.49 x 10~3 4.16 x 10"3 6.54 x 10"3 4.02 x 10"3 6.41 x 10"3 3.96 x 10"3 6.46 x 10"3 8.66 x 10"3 10.70 x 10"3 4.78 x 10~3 7.35 x 10"3 4.35 x 10"3 7.38 x 10~3 4.16 x 10~3 7.03 x 10~3 4.32 x 10"3 7.04 x 10"3 4.54 x 10"3 7.04 x 10"3 9.19 x 10"3 11.10 x 10"3 5.79 x 10"3 8.34 x 10"3 5.59 x 10"3 8.09 x 10"3 5.65 x 10"3 8.46 x 10"3 5.96 x 10"3 8.53 x 10"3 5.30 x 10"3 8.11 x 10"3 29 ------- TABLE 11. (Continued1) Amitrole (ppm) 50 50 50 50 50 50 PTU (ppm) 125 125 125 125 125 125 Control 0 0 0 0 0 0 Days on Study 90 90 60 60 30 30 90 90 60 60 30 30 90 90 60 60 30 30 Sex M F M F M F M F M F M F M F M F M F Heart (g) 2.66 3.04 2.83 3.45 2.83 3.32 2.66 2.82 2.58 3.05 2.76 3.10 2.72 3.26 2.58 3.05 3.39 3.84 x X X X X X X X X X X X X X X X X X io-3 io-3 io-3 _o 10 io-3 io-3 ID'3 io-3 io-3 io-3 io"3 io-3 io-3 ID'3 io-3 ID'3 _} 10 J _} 10 ^ Spleen (g) 1.65 x 2.08 x 1.67 x 2.15 x 1.74 x 2.48 x 0.93 x 1.03 x 1.24 x 1.40 x 1.43 x 1.45 x 1.71 x 1.95 x 1.24 x 1.40 x 2.12 x 2.38 x 10"3 io-3 ID'3 -3 10 J io-3 io-3 ID'3 io-3 io-3 io-3 io-3 io-3 io-3 io"3 io-3 io"3 _o 10 _0 10 Right Kidney Ovary (g) (paired) (g) 3.08 3.47 3.52 3.77 3.49 3.71 2.89 3.16 3.30 3.38 3.58 3.60 3.09 3.56 3.30 3.38 3.84 3.77 x X X X X X X X X X X X X X X X X X io-3 10"3 3.42 x 10"4 io-3 -3 -4 10 3.86 x 10 ID'3 10"3 6.20 x 10"4 io"3 10"3 3.08 x 10~4 ID'3 10"3 4.48 x 10"4 io-3 10~3 5.39 x 10"4 1Q-3 10~3 3.56 x 10"4 io-3 10"3 4.48 x 10"4 _o 10 -3 -4 10 6.20 x 10 Testicle (paired) (g> 1.07 x 10"2 1.12 x 10"2 - 1.31 x 10"2 1.69 x 10"2 1.71 x 10"2 _ 1.77 x 10"2 - 1.08 x 10"2 _ 1.71 x 10"2 _ _? 1.31 x 10 30 ------- TABLE 11. (Continued) Amitrole (ppm) 50 50 50 50 50 50 PTU (ppm) 125 125 125 125 125 125 Control (ppm) 0 0 0 0 0 0 Days on Study 90 90 60 60 30 30 90 90 60 60 30 30 90 90 60 60 30 30 Sex M F M F M F M F M F M F M F M F M F Liver (g) 3.56 x 10~2 3.59 x 10~2 3.88 x 10~2 3.95 x 10~2 4.38 x 10~2 4.95 x 10~2 3.17 x 10~2 3.42 x 10~2 3.37 x 10~2 3.68 x 10~5 3.67 x 10~5 4.10 x 10~5 3.31 x 10~2 3.60 x 10~2 3.79 x 10~2 3.82 x 10~2 4.22 x 10~2 4.43 x 10~2 Pituitary (g) 2.56 x 10~5 5.92 x 10~5 2.33 x 10"5 5.48 x 10~5 2.49 x 10~5 3.52 x 10~5 3.02 x 10~5 5.19 x 10~5 2.79 x 10~5 4.38 x 10~5 3.35 x 10~5 4.27 x 10~5 2.18 x 10~2 5.23 x 10~2 2.22 x 10~2 6.19 x 10~2 2.65 x 10~2 5.13 x 10~2 Thyroid (paired) (g) 13.43 x 10~5 14.23 x 10~5 8.12 x 10~5 9.11 x 10~5 22.91 x 10~5 22.80 x 10~5 42.90 x 10~5 45.20 x 10~5 35.90 x 10~5 44.43 x 10~5 25.53 x 10~5 36.81 x 10~5 5.80 x 10~5 8.81 x 10~5 6.42 x 10~5 8.59 x 10~5 6.70 x 10~5 7.14 x 10~5 Adrenal (mg) 0.99 x 10~4 2.09 x 10~4 1.00 x 10~4 2.52 x 10~4 1.14 x 10~5 2.44 x 10~5 1.08 x 10~4 1.40 x 10"4 1.01 x 10~4 1.68 x 10~4 1.08 x 10~4 1.64 x 10~4 0.98 x 10~4 2.33 x 10~4 1.15 x 10~4 2.40 x 10~4 1.26 x 10~4 2.58 x 10~4 31 ------- TABLE 12. ORGAN WEIGHT: BRAIN WEIGHT RATIO ETU (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 Days on Study 90 90 90 90 90 90 90 90 90 90 90 90 60 60 60 60 60 60 60 60 60 60 60 60 30 30 30 30 30 30 30 30 30 30 30 30 Sex M F M F M F M F M F M F M F M F M F M F M F M F M F M F M F M F M F M F Ovary (paired; g) 4.70 x 5.15 x 5.10 x 5.67 x 5.51 x 5.28 x 4.92 x 7.08 x 5.15 x 5.48 x 5.66 x 6.25 x 5.23 x 6.52 x 6.58 x 6.36 x 6.82 x 6.69 x _2 10 _9 10 * io-2 io-2 io-2 io-2 io-2 _2 10 * -2 10 i io-2 _2 10 _2 10 ^ _9 10 io-2 ID'2 _2 10 i -2 10 i io-2 Testicle (paired; g) 2.43 2.52 2.59 2.58 2.50 2.73 1.81 2.30 2.62 2.58 2.51 2.38 2.25 2.17 2.25 2.20 2.06 2.21 Pituitary (mg) 5.61 7.99 5.27 7.08 5.04 7.72 5.36 7.52 4.79 7.71 5.50 8.09 5.81 5.54 6.85 6.54 5.09 4.68 4.41 5.95 4.63 6.75 4.89 8.80 7.21 4.34 5.53 5.96 4.63 4.68 4.52 4.66 4.01 4.31 5.01 6.36 _3 x 10 .3 x 10 .3 x 10 _3 x 10 x 10"3 x 10~3 x 10"3 x 10"3 _3 x 10 x 10"3 _3 x 10 x 10"3 .3 x 10 x 10"3 _3 x 10 _T x 10 -3 x 10 -3 x 10 x 10"3 x 10"3 x 10"3 _3 x 10 x 10'3 -3 x 10 x 10"3 .3 x 10 x 10"3 x 10'3 x 10'3 x 10'3 x IO"3 .3 x 10 J .3 x 10 .3 x 10 .3 x 10 x 10"3 Thyroid (paired; g) 2.68 x 2.77 x 1.82 x 1.31 x 1.43 x 1.06 x 1.25 x 1.00 x 1.35 x 1.11 x 1.47 x 1.36 x 3.28 x 2.31 x 1.85 x 1.48 x 1.69 x 1.22 x 1.05 x 0.96 x 1.36 x 1.19 x 1.41 x 1.22 x 1.72 x 1.71 x 1.37 x 1.34 x 1.38 x 1.22 x 1.02 x 0.94 x 1.01 x 0.83 x 1.26 x 0.88 x _9 10 * -2 10 Z _2 10 * _9 10 l ID'2 io-2 ID'2 io-2 -2 10 i ID'2 _2 10 Z io-2 _2 10 i io-2 _9 10 L _9 10 l _9 10 l -2 10 i ID'2 io-2 io-2 -2 10 2 io-2 -2 10 ID'2 -2 10 i ID'2 io-2 ID'2 io-2 io-2 _9 10 * _9 10 i _2 10 i _2 10 i io-2 Adrenal (paired; mg) 2.26 2.60 2.35 2.88 2.49 3.13 2.38 3.37 2.44 3.51 2.47 3.61 2.36 2.49 2.79 3.41 2.38 3.16 2.44 3.37 2.52 3.11 2.53 3.44 2.23 2.21 2.42 3.27 2.57 3.42 2.52 3.15 2.36 3.43 2.38 3.19 _9 x 10 -2 x 10 -2 x 10 -2 x 10 x IO"2 x 10"2 x 10"2 x 10"2 -2 x 10 x 10"2 _2 x 10 x 10"2 _2 x 10 x 10"2 _2 x 10 -2 x 10 -2 x 10 -2 x 10 x 10~2 x 10"2 x 10"2 _2 x 10 x 10"2 -2 x 10 ^ x 10"2 -2 x 10 x 10"2 x IO"2 x 10"2 x 10"2 x 10"2 _9 x 10 _2 x 10 -2 x 10 -2 x 10 x 10"2 32 ------- TABLE 12. (Continued) (ppm) 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 625 625 125 125 25 25 5 5 1 1 0 0 Days on Study 90 90 90 90 90 90 90 90 90 90 90 90 60 60 60 60 60 60 6i> 60 60 60 60 60 30 30 30 30 30 30 30 30 30 30 30 30 Sex M F F F M F M F M F M I M F M F M F M F . M F M F M F M F M F M F M F M F Heart (g) 4. 3. 6. 4. 6. 5. 6. 4. 6. 4. 6. 5. 4. 3. 6. 5. 6. 4. 7. 4. 6. 4. 6. 4. 3. 3. 5. 4. 6. 4. 5. 4. 6. 4. 6. 4. 25 x 51 x 70 x 88 x 87 x 07 x 85 x 78 x 78 x 66 x 88 x 08 x 38 x 45 x 87 x 11 x 76 x 69 x 32 x 88 x 47 x 54 x 54 x 73 x 57 x 06 x 59 x 65 x 14 x 59 x 02 x 39 x 01 x 13 x 41 x 76 x ID'1 lo-1 1C'1 10'1 lo-1 lo-1 lo-1 ID'1 ID'1 10'1 10'1 10"1 ID'1 10'1 10'1 10'1 lO'1 ID'1 ID'1 10'1 ID'1 ID'1 ID'1 ID'1 lo-1 ID'1 ID'1 lo-1 10'1 lO'1 lo-1 ID'1 ID'1 ID'1 lo-1 ID'1 1 1 4 2 4 2 4 2 3 2 4 3 1 1 3 2 3 2 4 2 3 3 3 2 1 1 3 2 4 3 4 2 3 2 4 2 Spleen (g) .57 x .44 x .04 x .97 x .10 x .76 x .29 x .83 x .89 x .88 x .32 x .02 x .76 x .26 x .77 x .89 x .91 x .83 x .30 x .87 x .61 x .01 x .59 x .94 x .96 x .64 x .94 x .87 x .21 x .01 x .02 x .97 x .76 x .82 x .00 x .95 x lo-1 ID'1 10'1 lo-1 lo-1 10'1 lo-1 ID'1 lo-1 ID'1 ID"1 lo-1 ID"1 10'1 lo-1 10'1 10'1 10'1 10'1 lO'1 lo-1 ID'1 lo-1 ID'1 ID'1 ID'1 lo-1 ID'1 ID'1 ID'1 ID'1 ID'1 lO'1 ID'1 10'1 ID'1 Rt. Kidney (g) 4.67 x 3.89 x 8.22 x 5.12 x 7.32 x 5.27 x 7.25 x 5.32 x 7.57 x 5.21 x 7.81 x 5.51 x 4.92 x 4.07 x 7.33 x 5.09 x 8.05 x 5.31 x 8.44 x 5.08 x 7.81 x 5.37 x 7.93 x 5.50 x 4.67 x 3.81 x 6.72 x 5.03 x 6.87 x 5.11 x 6.75 x 4.70 x 6.53 x 4.51 x 7.25 x 4.67 x 10'1 lo-1 lO'1 lO'1 lo-1 lo-1 lo-1 ID'1 ID'1 10'1 lo-1 ID'1 lo-1 lo-1 ID'1 lO"1 ID'1- 10'1 10'1 10'1 10'1 10'1 lo-1 10'1 ID'1 lo-1 lo-1 ID"1 ID'1 ID'1 ID'1 ID'1 ID'1 10'1 ID'1 10'1 Liver (g) 4.20 3.92 9.30 5.40 8.56 5.71 8.10 5.68 8.80 5.86 8.35 5.57 4.56 4.60 8.71 5 47 10.20 5.48 9.14 5.60 8.40 5.17 8.35 5.43 4.90 4.71 8.37 5.31 7.91 5.44 8.17 5.02 7.38 4.83 7.97 5.49 33 ------- TABLE 12. (Continued) Amitrole (ppm) 50 50 50 50 50 50 PTU (ppm) 125 125 125 125 125 , 125 Control (ppm) 0 0 0 0 0 0 Days on Study 90 90 60 60 30 30 90 90 60 60 30 30 90 90 60 60 30 30 Sex M F M F M F M F M F M F M F M F M F Heart (g) 6.44 x 10"1 4.68 x 10"1 6.23 x 10"1 4.92 x 10"1 4.70 x 10'1 . 4.17 x 10"1 3.82 x 10'1 3.03 x 10"1 3.81 x 10"1 3.44 x 10"1 3.34 x lO'1 3.06 x 10"1 6.6>8 x 10"1 5.05 x 10"1 6.54 x 10"1 4.73 x 10'1 6.41 x 10"1 4.76 x 10'1 Spleen (g) 3.98 x 10'1 3.20 x 10"1 3.67 x 10"1 3.06 x 10"1 2.89 x 10'1 3.12 x 10"1 1.33 x 10'1 1.10 x 10"1 1.83 x 10"1 1.58 x 10'1 1.73 x 10"1 1.43 x 10"1 4.32 x 10"1 3.02 x lO'1 3.59 x 10"1 2.94 x 10"1 4.00 x 10'1 2.95 x 10'1 Rt. Kidney (g) 7.45 x 10'1 5.35 x 10"1 7.74 x 10"1 5.35 x 10"1 5.79 x 10"1 4.66 x 10"1 4.14 x 10"1 3.40 x ID'1 4.88 x 10"1 3.82 x 10'1 4.34 x 10"1 3.55 x 10'1 7.81 x 10"1 5.51 x 10"1 7.93 x 10"1 5.50 x 10"1 7.25 x 10'1 4.76 x 10"1 Liver (g) 8.59 5.53 8.52 5.62 7.26 6.22 4.54 3.68 4.97 4.15 4.45 4.04 8.35 5.57 8.35 5.43 7.97 5.49 ------- TABLE 12. (Continued) Amitrole (ppm) 50 50 50 50 50 50 PTU (ppm) 125 125 125 125 125 125 Control (ppm) 0 0 0 0 0 0 Days on Study 90 90 60 60 30 30 90 90 60 60 30 30 90 90 60 60 30 30 Ovary Sex (paired; g) M F 5.28 x 10~2 M -2 F 5.50 x 10 M _2 F 7.79 x 10 M F 4.17 x 10~2 M F 5.06 x 10~2 M F 5.32 x 10"2 M F 5.51 x 10"2 M F 6.21 x 10~2 M F 6.69 x 10"2 . Testicle (paired; g) 2.58 2.47 2.17 2.42 ._ 2.52 2.14 2.73 2.38 2.21 Pituitary (mg) 6.20 9.13 5.12 7.79 4.13 4.42 4.39 5.58 4.11 4.94 4.05 4.21 5.50 8.09 4.89 8.80 5.01 6.36 x X X X X X X X X X X X X X X X X X io-3 io-3 io"3 _3 10 J io"3 _T 10 J io-3 io-3 io"3 io-3 _} 10 J 10"3 _} 10 J io-3 _} 10 J io-3 io-3 io"3 Thyroid (paired; g) 3.23 2.20 1.79 1.30 3.80 3.13 6.14 4.86 5.30 5.01 3.09 3.64 1.47 1.36 1.41 1.22 1.26 0.89 x x X X X X X X X X X X X X X X X X io-2 io-2 io"2 -2 10 io-2 _2 10 Z io-2 io-2 io"2 io-2 _2 10 Z io-2 _? 10 L io-2 _o 10 ^ io-2 io-2 io-2 Adrenal (paired; mg) 2.40 x 3.22 x 2.20 x 3.59 x 1.88 x 3.67 x 1.55 x 1.50 x 1.49 x 1.90 x 1.30 x 1.62 x 2.47 x 3.61 x 2.53 x 3.41 x 2.38 x 3.19 x 10-2 io-2 io"2 _o 10 io-2 _2 10 io-2 io"2 io-2 io"2 _ 0 10 io-2 7 10 io2 7 i fl- ic"2 io-2 io-2 ------- TABLE 13. ABNORMAL CHANGES OBSERVED FOR LIVER, SKIN AND THYROID Tissue Change Enlarged Thyroids; Red Thyroids Normal Size but Red Centrilobular Congestion; liver Alopecia Small Adrenals Enlarged Thyroids; Red Centrilobular Congestion; liver Alopecia Days on Study 30 30 30 30 30 30 30 30 30 30 60 60 60 60 60 60 Sex M F M F M F M F M F M F M F M F PTU Amitrole 125 50 10 10 0 0 0 0 0 0 0 0 10 10 0 0 0 0 10 10 0 0 0 0 0 0 8 2 5 2 2 0 0 0 ETU 625 10 5 0 0 0 0 8 4 0 0 5*** 9 0 0 5 9 125 8 2 0 0 0 0 0 0 0 0 6 1 2 0 0 0 25 0 0 3 2 0 0 0 0 0 0 1 0 3 0 0 0 5 0 0 0 0 0 0 0 0 0 0 2 2 2 . 0 0 0 Control** 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 **** Enlarged Thyroids; Red Alopecia Centrilobular Congestion; liver Small Adrenals Adenocarcinoma of Salivary Gland 90 90 90 90 90 90 90 90 90 90 M F M F M F M F M F 10 10 0 0 0 0 8 9 0 1 10 5 0 0 3 2 0 0 0 0 8 6 6 4 0 0 0 0 0 0 10 6 0 0 9 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 6 2 0 0 0 0 0 0 0 0 1 0 0 0 0 0 *Presented as the number of animals with the indicated tissue change, out of the 10 animals evaluated. **Twelve male and eleven female control rats were evaluated from 30 day group. Twelve male and twelve female rats were evaluated from the 60 and 90 day control groups. ***Five *male rats and one female rat from the 625 ppm 60 day group died prior to the end of the study. Therefore, the values for this one group are based on the evaluation of five male and one female rat. ****Two female rats died prior to the end of the 90 days. Therefore, the values for females on this one group are based on eight rats. ------- TABLE 14. GRADING OF DEGREE OF HYPERPLASIA FROM MICROSCOPIC APPEARANCE OF THE THYROID GLAND Grade of Hyperplasia Description of Change in Morphology 0 Completely normal appearing gland. >1 Very slightly altered lining cells and scalloping of colloid. 1 Distinct hyperplasia or hypertrophy of lining cells and a moderate reduction of colloid. >2 Hyperplastic change of lining cells and folding of follicular wall with a moderate reduction of colloid. 2 Moderate hyperplasia of lining cells, increase in apparent number of micro- follicular follicles reducing apparent colloid to less than fifty percent of normal. >3 More extensive microfollicular pattern but still retaining approximately twenty-five percent colloid. 3 Marked hyperplasia of lining cells with virtually all microfollicular follicles and nearly complete absence of colloid. 37 ------- TABLE 15.THYROID HYPERPLASIA OBSERVED IN ETU TEST ANIMALS Degree of Hyperplasia 0 .>! 1 >2 2 >3 3 0 >1 1 >2 2 >3 3 0 >1 1 >2 2 >3 3 Days on Study 30 30 30 30 30 30 30 60 60 60 60 60 60 60 90 90 90 90 90 90 90 PTU 125 0 0 0 0 8 3 9 0 0 0 0 0 17 3 0 0 0 0 1 10 9 Amitrole 50 0 0 0 . 0 0 5 15 0 4 5 8 3 0 0 0 5 14 0 1 0 0 625 0 0 2 4 12 2 0 0 0 2 2 10 0 0 0 0 1 1 12 3 1 125 0 0 18 1 1 0 0 1 3 7 5 2 0 2 1 0 14 3 1 0 1 ETU 25 0 9 11 0 0 0 0 7 2 0 7 4 0 0 3 8 9 0 0 0 0 5 1 6 13 0 0 0 0 4 7 9 0 0 0 0 6 8 6 0 0 0 0 1 0 7 13 0 0 0 0 1 9 10 0 0 0 0 6 6 8 0 0 0 0 0 4 9 10 0 0 0 0 5 10 9 0 0 0 0 12 9 3 0 0 0 0 38 ------- TABLE 16. CHANGES IN THYROID MORPHOLOGY IN RATS WHICH INGESTED 625 PPM ETU FOR NINETY DAYS* Rat Number 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 Sex M M M M M M M M M M F F F F F F F F F F Solid Adenomas 1 1 1 0 1 0 0 2 0 0 Died Died 2 0 0 0 0 0 1 0 Cystic Adenomas 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Adenomatous Changes 0 2 0 1 2 0 0 0 0 0 1 0 0 1 0 0 0 0 Cyst-like Follicles 0 0 0 0 0 1 0 0 1 0 0 1 0 0 0 1 0 0 * Thyroids examined by serial sectioning. 39 ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) i. REPORT NO. EPA-600/1-77-023 3. RECIPIENT'S ACCESSION NO. . 4. TITLE AND SUBTITLE DIETARY SUBACTURE TOXICITY OF ETHYLENE THIOUREA IN THE LABORATORY RAT 5. REPORT DATE May 1977 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO. Ralph I. Freudenthal 9. PERFORMING ORGANIZATION NAME AND ADDRESS Battelle Columbus Laboratories 505 King Avenue Columbus, Ohio 43201 10. PROGRAM ELEMENT NO. 1EA615 11. CONTRACT/GRANT NO. 68-02-1715 12. SPONSORING AGENCY NAME AND ADDRESS Health Effects Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Research Triangle Park, N.C. 27711 13. TYPE OF REPORT AND PERIOD COVERED HERL-RTP 14. SPONSORING AGENCY CODE EPA 600/11 15. SUPPLEMENTARY NOTES 16. ABSTRACT Ethylene thiourea (ETU) was fed to groups of rats at 0, 1, 5, 25, 125 or 625 ppm for up to 90 days. Other groups of rats received either propulthiouracil (PTU; 125 ppm) or amitrole (50 ppm) in their diets as positive controls. Only those rats which received ETU at 125 or 625 ppm and those ingesting PTU or amitrole demonstrated a measurable toxic response. This toxicity was reflected as an alteration in thyroid function and a significant change in thyroid morphology. Ingestion of 625 ppm ETU or 125 ppm PTU resulted in very substantial decreases in serum triiodothyronine (T-3) and thyroxine (T-4). Marked increases in serum thryroid stimulating hormone (TSH) levels were found in the 625 and 125 ppm ETU rats, the 125 PTU rats and the rats receiving amitrole, at each time point this hormone was measured. A decrease in iodide uptake by the thyroid was also found in the rats ingesting 625 ppm ETU. Wnile a statistically significant increase in serum T-4 and degree of thyroid hyper- plasia was observed for the rats ingesting 25 ppm ETU for 60 days, normal thyroid normone levels and thyroid morphology was found in the rats on 25 ppm ETU for either JO or 90 days. Based on biochemical and microscopic changes examined, the no-effect level for dietary ETU in this 90-day study is considered to be 25 ppm, equivalent to an average intake ranging from 19.5 mg/kg body weight at Week 1 to 12.5 mq/kq body weight at Week 12. . 3/ y y 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group thioureas toxicity toxic tolerances rats ethylene thiourea ETU 06, T 13. DISTRIBUTION STATEMENT RELEASE TO PUBIJC 19. SECURITY CLASS (This Reportj UNCLASSIFIED 21. NO. OF PAGES 20. SECURITY CLASS (Thispage) UNCLASSIFIED . 22. PRICE EPA Form 2220-1 (9-73) 40 ------- INSTRUCTIONS 1. REPORT NUMBER Insert the EPA report number as it appears on the cover of the publication. 2. LEAVE BLANK 3. RECIPIENTS ACCESSION NUMBER Reserved for use by each report recipient. 4. TITLE AND SUBTITLE Title should indicate clearly and briefly the subject coverage of the report, and be displayed prominently. Set subtitle, if used, in smaller type or otherwise subordinate it to main title. When a report is prepared in more than one volume, repeat the primary title, add volume number and include subtitle for the specific title. 5. REPORT DAtE Each report shall carry a date indicating at least month and year. 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EPA Form 2220-1 (9-73) (Reverse) ------- |