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Background Diethyl hexyl phthalate (DEHP) is a chemical plasticizer that causes significant neurological impairments after prenatal exposure. The impact of these exposures on cognitive recovery after severe traumatic brain injury (sTBI) has never been studied. We hypothesized that prenatal exposure to DEHP will impair cognitive recovery after a sTBI in a sex-specific manner. Methods To test this hypothesis, six-month-old male and female offspring that were prenatally exposed to DEHP were subjected to controlled cortical impact injuries, and their spatial memory was tested weekly using a Morris Water Maze (MWM) test for 4 weeks post-sTBI. Results We observed that DEHP-exposed male rats demonstrated significantly impaired spatial memory up to four weeks post-sTBI when compared to controls. In contrast, DEHP-exposed female rats showed no detectable impairment in spatial memory recovery compared to injured controls. These observations were accompanied by marked increases in neurotransmitter levels in the cortex and dopamine levels in the hippocampus of female, but not in male rats. No significant differences in lesion area and number of hippocampal neurons were observed in both sexes. Conclusion These results suggest that prenatal exposure to DEHP may have long lasting effects in the brain that could lead to impaired recovery specifically in male subjects following post-sTBI.

The objective of this study was to evaluate the effects of gestational exposure to low doses of bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) on pregnancy outcomes and offspring development. Pregnant Sprague-Dawley rats were orally dosed with vehicle, 5 μg/kg body weight (BW)/day of BPA, BPS and BPF, or 1 μg/kg BW/day of BPF on gestational days 6–21. Pregnancy and gestational outcomes, including number of abortions and stillbirths, were monitored. Male and female offspring were subjected to morphometry at birth, followed by pre- and post-weaning body weights, post-weaning food and water intakes, and adult organ weights. Ovarian follicular counts were also obtained from adult female offspring. We observed spontaneous abortions in over 80% of dams exposed to 5 μg/kg of BPF. BPA exposure increased Graafian follicles in female offspring, while BPS and BPF exposure decreased the number of corpora lutea, suggesting reduced ovulation rates. Moreover, BPA exposure increased male kidney and prostate gland weights, BPF decreased epididymal adipose tissue weights, and BPS had modest effects on male abdominal adipose tissue weights. Prenatal BPS exposure reduced anogenital distance (AGD) in male offspring, suggesting possible feminization, whereas both BPS and BPA induced oxidative stress in the testes. These results indicate that prenatal exposure to BPF affects pregnancy outcomes, BPS alters male AGD, and all three bisphenols alter certain organ weights in male offspring and ovarian function in female offspring. Altogether, it appears that prenatal exposure to BPA or its analogues can induce reproductive toxicity even at low doses.

Prenatal programming with endocrine disrupting chemicals (EDCs), in particular the ubiquitous plasticizers bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP), can induce long-lasting behavioral changes in rats. Additionally, changes in estrogen are correlated with the development of mood disorders in women; however, the underlying neurobiological mechanisms are unclear. This study was conducted to determine the cumulative effects of prenatal exposure to EDCs followed by chronic estradiol treatment in adult female rats on monoamine levels in the prefrontal cortex (PFC) and hippocampus (HC). Dams were orally administered saline (control; 10 µL/kg), BPA (B; 5 µg/kg), DEHP (D; 7.5 mg/kg) or a combination of BPA+DEHP (B+D) during days 6 through 21 of pregnancy. Adult female offspring were sham-implanted or implanted with pellets that release 17β-estradiol (E2) for 90 days (20 ng/day; Innovative Research America). The offspring then underwent a battery of behavioral tests at the end of treatment. Brains collected from the offspring were sectioned and the PFC and HC were microdissected and analyzed for levels of norepinephrine (NE), dopamine (DA) and serotonin (5-HT), using High-Performance Liquid Chromatography (HPLC). Significant reductions in monoamine levels were observed in the PFC while NE and 5-HT levels were markedly reduced in the HC after prenatal exposure to D or BD. BPA’s effects on monoamines were comparatively modest. E2 exposure increased DA but decreased 5-HT levels in the PFC of control animals. Prenatal exposure to EDCs made the offspring non-responsive to E2. The marked reduction in monoamine levels could have implications for learning and memory.

Bisphenol A (BPA) and Diethylhexyl Phthalate (DEHP) are well-studied endocrine disrupting chemicals (EDCs), however, the effects of mixtures of these EDCs are not. To assess the consequences of prenatal exposure to a mixture of these EDCs, dams were orally administered either saline (control), BPA (5 μg/kg BW/day), high dose DEHP (HD-D; 7.5 mg/kg BW/day), or a combination of BPA with HD-D in experiment 1; saline, BPA (5 μg/kg BW/day), low-dose DEHP (LD-D; 5 μg/kg BW/day) or a combination of BPA with LD-D in experiment 2. Gestational weights, number of abortions, litter size and weights, number of live births and stillbirths were recorded. Morphometric measures were obtained at birth and body weight, food and water intake were monitored weekly from postnatal weeks 3–12. Offspring were sacrificed at 16–24 weeks of age and organ weights were measured. The abortion rate of dams exposed to HD-D and the mixtures, BPA + LD-D and BPA + HD-D were higher at 9, 14 and 27% respectively. Prenatal exposure to BPA or HD-D significantly decreased relative thymus weights in male but not female offspring. Apoptotic cells were detected in thymus sections of both male and female offspring prenatally exposed to DEHP. Relative heart weights increased in BPA + HD-D exposed male offspring compared to the other groups. The results indicate that a mixture of BPA and DEHP, produced a pronounced effect on pregnancy outcomes. Male offspring appear to be more susceptible to the programming effects of these EDCs or their mixture suggesting a need to reconsider the possible additive, antagonistic or synergistic effects of EDC mixtures.