xvEPA
United States
Environmental Protection
Agency
Health Effects Research
Laboratory
Research Triangle Park NC 2771 1
Research and Development
EPA-600/S1-81-015 Aug 1981
Project Summary
Sensitive Biochemical and
Behavioral Indicators of
Trace Substance Exposure:
Part II. Platinum
Edward J. Massaro, Bradley A Lown, John B. Morganti, Carl H. Stineman,
and Rosemary B. D'Agostino
The overall objective of this project
was to characterize Pt [Pt(SO4)2,
NA2PtCle] intoxication in a model
mammalian system (the mouse) em-
ploying acute (single) and serially
repeated (multiple) dose exposure
paradigms. Platinum lethality para-
meters were defined in both sexes of
the adult mouse and Pt tissue/organ
distribution was monitored as a func-
tion of time and dose. In coordination
with the tissue distribution study,
investigations of the effects of Pt on
selected parameters of open field,
exploratory and social behavior, pas-
sive avoidance learning and the acqui-
sition of two-way active avoidance
learning were undertaken. Correla-
tions among tissue levels of Pt and
open field behavioral parameters (am-
bulations and rearings) were probed
employing statistical methodology.
Since numerous xenobiotics are
known to cross the placenta and/or
accumulate in maternal milk, studies
of Pt tissue/organ distribution in the
gravid female and the embryo/fetus/
offspring were undertaken. Platinum
levels were monitored as a function of
time. Coordinate studies examined
developmental and behavioral para-
meters of the offspring (as neonates,
pups and adults) of exposed mothers.
In addition, maternal behavior was
examined as a function of pup retrieval
and neonate and pup activity levels
were assessed. Ambulations and rear-
ings in the open field, passive avoid-
ance learning and rotarod performance
were assessed in adult offspring of
exposed mothers.
This Project Summary was devel-
oped by EPA's Health Effects Research
Laboratory, Research Triangle Park,
NC, to announce key findings of the
research project that is fully docu-
mented in a separate report of the
same title (see Project Report ordering
information at back).
Results
Presently, we have no data to explain
the disproportionately high tissue con-
centrations of Pt in animals receiving
Pt(S04)z intragastrically (IG) at the LD25
level as compared to the LD5 level.
Conceivably, the higher Pt dose may
perturb the Gl tract in some manner,
resulting in facilitated Pt absorption.
The high Pt concentrations found in the
blood of such animals may damage the
kidneys (which normally eliminate Pt
quite efficiently), thereby decreasing Pt
excretion and increasing tissue uptake.
In addition, it is well known that some
metals, such as cadmium and lead, are
able to induce the synthesis of their own
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binding proteins. Platinum may have a
similar ability.
The analysis of variance (ANOVA) of
the open field behavioral measures
revealed that the higher Pt dose de-
pressed ambulations significantly and
rearings marginally, relative to other
treatments, from 4 hours through 7
days post administration. A correlation
analysis revealed highly significant
negative correlations between behavioral
measures and tissue levels of Pt in all
tissues except brain and muscle. Since
brain Pt levels were not related to
behavior, it is not clear how non-CIMS
tissue Pt levels affect behavior. In
earlier work with alveolar macrophages
in tissue culture, a 50% loss of viability
(ability to exclude trypan blue) after a 20
hour exposure to 300 mM PtCI* was
reported. Protein and RNA synthesis
were inhibited by 50% by 60 mM Pt and
DNA synthesis was inhibited by 50% by
10 mM Pt. The maximum tissue Pt
concentration observed in our study
was 50 ppm in the kidney, 4 hours post
administration. Fifty ppm is approx-
imately equivalent to 250 mM Pt. There-
fore, cellular processes may have been
disrupted to some extent in the LD25
animals which, in turn, may produce a
general malaise and depression of the
activity component of certain behaviors.
Pt(SO4)2-Single (Acute) Dose
Effects on Exploratory
Behavior
The high rate of explorations of the 4
hour low pH control group, for which no
satisfactory explanation is presently
available, may have sufficiently accen-
tuated the difference between the 4
hour time point and all other times of
observation to account for the finding of
a significant main effect of time as well
as the significant time by treatment
interaction.
At 1, 3 and 7 days post IG administra-
tion, the mean number of explorations
for the 2 Pt groups (LDS, LD25) and the
low pH control group was lower than
that of the saline control group, but not
significantly. Possibly, this trend was
due to some nonspecific effect of the
low pH or sulfate content of the solutions.
In any case, it is apparently not a specific
Pt effect. Thus, in this study, Pt exposure
per se, does not appear to have effected
changes in exploratory behavior.
Pt(SO4)2-Single (Acute) Dose
Effects on Activity Wheel Per-
formance
Platinum at either the LD5 or LD25
levels appeared not to affect wheel
running scores. All groups exhibitedthe
lowest scores during the first 24 hours
post administration. This may have
resulted from trauma induced by han-
dling the dose administration. The
relative depression of scores observed
on the last 2 days of testing may have
been due to the effect of time (habitua-
tion). Trend analysis demonstrated that
the performance curves of all treatment
groups followed the same trend, inde-
pendent of treatment. Thus, there were
no overt effects of Pt exposure on
activity wheel performance.
PtfSOth-Single (Acute) Dose
Effects on Passive Avoidance
Learning
Intragastric administration of PtfSCMg
at the LDs or LD2s levels had no observ-
able effect on passive avoidance learning
by the adult mouse.
Pt(SO4)2-Single (Acute) Dose
Effects on Active Avoidance
Learning
Platinum sulfate at the LD5 or LD25
levels had no effect either on the acqui-
sitions of two-way active avoidance
learning or activity in the apparatus.
Pt(SO4)2-Single (Acute) Dose
Effects on Social Behavior
At the IG LD5 or LD25 levels, Pt (SO4)2
had no effect on the measure of murine
social behavior investigated.
NazPtCk-Single (Acute) Dose
Tissue Distribution and Open
Field and Exploratory
Behavioral Studies
Relative to the dose administered, the
fairly low tissue/organ Pt levels observed
suggest that Na2PtCI6 is only poorly
absorbed from the gut. With the excep-
tion of the spleen, the biological half-life
of Pt administered as Na2PtCI6 appears
to be short.
Na2PtCle depressed ambulations and
rearings in the open field. However, the
effect was transitory and clear-cut
effects were found only at 4 hours post
administration. At 1 and 3 days post
administration, the LD5 exposed groups
had depressed rearings relative to the
saline controls groups but not the low
pH control groups.
Na2PtCle had no observable effect or
exploratory behavior at 1, 3 and 7 day;
post administration. Unfortunately
exploratory behavior was not examinee
4 hours post administration when th<
strongest depression of open fielc
behavior had been observed.
Pt(SO4)2-Multiple (Serially
Repeated) Dose Effects on
Tissue Distribution and
Open Field Behavior
This study was undertaken to gair
insight into the effects of subchronn
exposure to Pt on certain behaviors o
the mouse. Subchronic exposure wa:
simulated via the use of a limitei
repeated dose experimental design (1 ti
10 doses) Adult male mice were sub
jected to repeated IG administratioi
(every 72 hours) of relatively high dose
of Pt(S04)2 (each dose equaled the 7da
LDi, which is approximately 40% of th'
7 day LD5o). This design resulted only ii
marginal adverse effects on the genere
activity and exploratory behavior of th.
adult animal. Tissue/organ Pt level^
while highly variable, generally in
creased with the number of dose
except for the brain, in which no Pt wa
detected in any animal. The absence c
Pt in the brain is not surprising since th
highly charged Pt cation should b
excluded by the blood brain barrier. 0
the three behavioral measures studiec
only rearings in the open field showed
significant correlation with tissue F
levels. Since this correlation involved
number of tissues and not the brain,
general systemic effect, rather than
neurotoxic effect, seems to be mdicatec
Inorganic Pt compounds have bee
shown to inhibit DNA, RNA and protei
synthesis in tissue culture. Thus, it ma
be that Pt has a depressive effect o
cellular metabolic processes and e>
posure to Pt above a threshold lev(
results in general malaise which i
reflected in the slight depression i
behavior observed in this study.
Pt(SO4J2 Developmental
Studies
The predominant effect of matern;
administration of Pt(S04)2 on days 7 ar
12 of gestation was in offspring weigh
The in utero Pt exposed offspring wei
lighter than low pH exposed offsprin'
This effect was powerful, beginning c
day 0 and continuing through day i
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post partum. As indicated by the signifi-
cant multivanate effect for postnatal
exposure, type of foster mother exposure
also has a significant effect on offspring
weight. Thus, on day 45 post partum,
pups (exposed to Pt or low pH in utero)
reared by Pt exposed foster mothers
weighed less than Pt or low pH gesta-
tionally exposed pups reared by low pH
exposed mothers. The reason for the
weight differences is unknown. How-
ever, it may be that reduced weight
could have important consequences,
such as reduced viability.
Administration of PtfSCUfe to lactating
mothers resulted in symptoms of toxicity
in offspring. Offspring assigned to
mothers administered Pt during lactation
exhibited depressed neonatal activity
(p< 0.006) and lower adult weights (p<
0.015) than controls. Pt may have
affected these offspring directly through
the maternal milk supply and/or in-
directly by affecting some aspect of
maternal behavior.
PtCle Developmental
Tissue Distribution and
Behavioral Studies
Maternal blood, kidney, and whole
embryo Pt levels were highest 1 day
post administration of NajPtCle on day 7
of gestation. No Pt was detected in the
maternal brain. By day 5 post adminis-
tration, Pt was undetectable in fetal
tissues, but the placental level was 2.5
fold greater than that of maternal blood.
Except for the maternal spleen, the Pt
levels of maternal, fetal, and placental
tissues peaked on day 1 post adminis-
tration of NaaPtCle on day 12 of gesta-
tion. A low level of Pt (0.43 ± 0.01 ppm)
was detected m maternal brain tissue.
Placental Pt levels were greater than
blood levels throughout the course of
the experiment, reaching concentration
factors, compared to blood, of 1.3 and
4 2 on days 1 and 5 post administration,
respectively.
Whole body Pt levels in the suckling
offspring of dams receiving Pt on day 2
post partum were highest on day 1 post
administration. By day 1 2 post adminis-
tration, except for the digestive tract and
its contents, no Pt was detectable in the
tissues of the sucklings.
Effects of maternally administered
NaaPtde on neonatal and adult off-
spring behavior were limited to day 12
gestational exposure. The neonatal
effects were expressed as lower day 8
post partum activity scores for in utero
Pt exposure compared to PBS exposure.
For the adult offspring, there was a
prenatal x postnatal exposure interaction
indicating that Pt exposed mothers
reduced the performance of offspring on
those tasks with a large activity compo-
nent (i.e., ambulations, passive avoid-
ance trial 1 latency and passive avoid-
ance difference scores). In this case,
gestational exposure to Pt appears to
have persistent effects on the mother
that are transmitted postnatally to
offspring. This may occur directly
through residual Pt in the milk or
indirectly through maternal behavioral
alteration resulting in neglect of the
offspring.
Conclusions
In summary, PtfSCMz administered
via the IG route appears to be poorly
absorbed. However, with the exception
of brain tissue, the absorbed Pt achieves
general systematic distribution. With
repeated exposure, tissue concentra-
tions tend to increase with dose; again,
with the exception of brain which did
not accumulate Pt. While Pt did affect
behavior under conditions of single and
multiple dose exposure, these effects
were weak except when very high [LDzs)
individual doses were employed In the
latter case, the behavioral effects were
more pronounced and lasted for up to 7
days post administration (end of observa-
tion). The consistent pattern of rela-
tionship between tissue levels of Pt and
behavior is suggestive of interference
with cellular processes induced by Pt at
concentrations greater than some
threshold value. This interference is
manifested as behavioral malaise.
It is difficult to predict the potential
danger of increased anthropogenic
redistribution of Pt in the environment.
Toxicity has been observed in humans
exposed to high Pt levels in the work-
place or during antitumor chemotherapy.
However, such dose levels are many
times those that would ever by expected
to occur in the general environment.
Nevertheless, since exposure to Pt
appears to alter certain behavior of the
mouse, the possibility gf subtle adverse
biological and behavioral effects result-
ing from long-term low level (environ-
mental) exposure of humans cannot be
disregarded especially in the light of the
fact that Pt can be methylated in a
manner analagous to that of mercury.
By altering its physicochemical proper-
ties, methylation may, as in the case of
mercury, greatly enhance the toxicity of
Pt and its bioaccumulatability
Edward J. Massarois with the Center for Air Environment Studies, Pennsylvania
State University, University Park, PA 16802; Bradley A. Lown and John B.
Morganti are with the Department of Psychology, State University College at
Buffalo, Buffalo, NY 14222; Carl H Stineman and Rosemary B. D'Agostino are
with the School of Medicine, State University of New York at Buffalo, Buffalo,
NY 14214
George M. Goldstein is the EPA Project Officer (see below).
The complete report, entitled "Sensitive Biochemical and Behavioral Indicators
of Trace Substance Exposure. Part II. Platinum," (Order No. PB 81-160 897;
Cost' $8 00, subject to change) will be available only from-
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone 703-487-4650
The EPA Project Officer can be contacted at
Health Effects Research Laboratory
U S Environmental Protection Agency
Research Triangle Park, NC 27711
us GOVERNMENT PRINTING OFFICE 1981 -757-012/7283
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Environmental Protection
Agency
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