Monograph on the Potential Human Reproductive and ... - OEHHA

Target intakes were B0, 0.0009, 0.018, 0.27, 4.5, 45, and
450 mg/kg bw/day in males and 0.001, 0.02, 0.30, 5, 50,
and 500 mg/kg bw/day in females. Actual intakes were
0.0007–0.003, 0.015–0.062, 0.22–0.73, 4.1–15.4, 37.6–167.2,
and 434–1823 mg/kg bw/day. The study was designed to
include low-dose exposures reported to increase prostate
weights (Nagel et al., 1997; vom Saal and Sheehan, 1998)
and maximally tolerated doses expected to result in
toxicity. Concentration, stability, and homogeneity of
bisphenol A in feed were verified. During the study,
body weight and food intake were measured and
animals were examined for clinical signs. F0 males were
killed and necropsied following delivery of the F1 litter.
Histopathological evaluation of organs was conducted in
all control animals and 10 animals/bisphenol A dose
group. Reproductive organs were weighed and sperm
endpoints were evaluated. F 0 females were killed and
necropsied following weaning of their litters. Selected
organs were weighed and ovarian primordial follicles
were counted.
On PND 4, F1 litters were culled to 10 pups, with equal
numbers of each sex when possible. Endpoints examined
in pups included growth and survival in the prenatal
period and retained areolae or nipples on PND 11–13. At
weaning on PND 21, 30 F 1 offspring/sex/group were
randomly selected and exposed to bisphenol A in the
diet according to the same protocol as F 0 rats. Those
selected offspring were monitored for vaginal opening
and preputial separation and later mated. Up to 3 F1
weanlings/sex/litter were killed for organ weight
measurement. Mating and evaluation of F1 offspring
were conducted according to the same procedures
described for F 0 rats. The same procedures were repeated
in F 2 rats and F 3 litters during the lactation period.
Anogenital distance was measured in F 2 and F 3 rats at
birth. Following weaning of F3 offspring, up to 3/sex/
litter were randomly selected for necropsy. Thirty/sex/
dose were selected for evaluation of vaginal patency,
preputial separation, and estrous cyclicity. Bisphenol A
exposure was continued in those offspring until they
were killed B10 weeks following weaning. F 3 offspring
were not mated, but necropsy evaluations were conducted
as described above for previous generations.
Statistical analyses for quantitative continuous data
included Bartlett test for homogeneity of variances,
ANOVA, Dunnett, linear trend, Kruskal–Wallis, or
Mann–Whitney U tests. Frequency data were analyzed
by w 2 , Fisher exact, and Cochran–Armitage tests. Covariance
and correlations analyses were also conducted.
Treatment-related systemic findings with available
quantitative information in adult rats are summarized
in Table 93. Body weights and body weight gain were
consistently lower in F0, F1, F2, and F3 adult rats of the
750 and 7500 ppm dose groups, including during gestation
and lactation periods. Terminal body weight effects
are summarized in Table 93. Terminal body weight was
reduced in all generations at 7500 ppm and in F 1 females
and F 1 and F 2 males at 750 ppm. There were no consistent
or clearly treatment-related effects on feed intake. No
treatment-related clinical signs were reported. In the
7500 ppm group, absolute weights of the liver in males
and the kidney in both sexes were decreased across
generations. Relative weights were either increased or
did not attain statistical significance. [According to
Table 2 of the study, absolute liver weights were also
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decreased in males of the 750 ppm group. The study
authors also mentioned reductions in weights of
adrenal glands, spleen, pituitary, and brain at the
high-dose, but there were no data shown in the report
for those endpoints.] Other changes in non-reproductive
organ weight occurred sporadically at lower dose and
were not dose-related or consistent across generations.
Relative organ weight changes that consistently attained
statistical significance at the highest dose are summarized
in Table 93. Histopathological analyses revealed a
higher incidence of mild renal tubular degeneration and
chronic hepatic inflammation in F 0,F1, and F2 but not F3
females of the 7500 ppm group.
Treatment-related effects on reproductive endpoints in
adult animals are summarized in Table 93. In evaluating
organ weights, the study authors only considered organ
weight effects to be biologically significant if statistically
significant results were obtained in the same direction for
absolute and relative weights. Therefore, the study
authors concluded that the only treatment-related organ
weight effects were reduced absolute and relative ovary
weights. [Numerous statistically significant effects on
reproductive organ weights were reported in Table 2 of
the study. Reductions in testes, epididymides, prostate,
and seminal vesicle weights were observed in most
generations of the 7500 ppm group. When adjusted for
body weight, organ weights were either increased or
did not differ significantly from controls.] Relative
reproductive organ weight changes that consistently
attained statistical significance at the highest dose are
summarized in Table 93. The authors reported no effect
on mating, fertility, pregnancy, or gestational indices.
[With the exception of gestational length, data were not
shown by study authors.] Precoital interval, postimplantation
loss, estrous cyclicity, and reproductive
organ histopathology were also unaffected by bisphenol
A treatment. In the high-dose group, there was no
adverse effect on paired ovarian primordial follicle
counts but counts were significantly increased by 43%
in the F 0 generation. Implantation sites were decreased in
F 0,F 1, and F 2 dams of the 7500 ppm group. The only
significant effects on sperm endpoints were decreased
epididymal sperm concentration in F 1 males and
decreased daily sperm production in F3 males of the
7500 ppm dose group. There were no effects on sperm
morphology or motility. The study authors considered
sperm to be unaffected by treatment.
Treatment-related effects observed in developing rats
are summarized in Table 94. The number of live pups/
litter was reduced in F 1,F 2, and F 3 litters of the 7500 ppm
group. Body weights of F 1, F 2, and F 3 pups of the
7500 mg/kg bw/day groups were lower during the
lactation period. Some small (B5%) decreases in pup
body weight during the lactation period at lower
doses were apparently not considered treatment-related
by study authors. Postnatal survival was unaffected by
bisphenol A treatment. In male rats, there were no
effects on anogenital distance or the presence of
areolas or nipples. Anogenital distance was significantly
increased in F2 females at all doses except 75 and
7500 ppm; there was no affect on anogenital distance in
F3 females. The study authors did not consider
anogenital distance effects to be biologically or toxicologically
significant. Vaginal patency was delayed in F1, F2,
and F 3 females, and the effect remained significant