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
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
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This report has been assigned to the ENVIRONMENTAL HEALTH EFFECTS RE-
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This document is available to the public through the National Technical Informa-
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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
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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
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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
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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
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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
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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
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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
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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.
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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
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(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
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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.
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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
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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. .
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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.
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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.
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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
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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
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