Bisphenol A (BPA) is a ubiquitous endocrine disrupting compound that is detectable in over 90% of Canadians and Americans. It was originally found to be an estrogenic compound, but can also act through a variety of other hormone systems, including glucocorticoids and, according to in vitro studies, also exerts anti-androgenic activity though the in vivo evidence for this claim is inconclusive. Some work has suggested that reproductive behaviours are impaired in males and there is conflicting evidence as to how emotionality may be affected. However, this field of research has been somewhat controversial, as governments worldwide have accepted that BPA is safe at low doses, despite the experimental and epidemiological evidence that low doses are in fact more likely to exert negative effects. As such, this research program is examining a wide range of doses of BPA administered to rats both pre- and postnatally. Reproduction, anxiety, learning and learned helplessness were then tested in adulthood. This data indicates that low doses of BPA administered perinatally can inhibit the reproductive behaviour of males even after multiple experiences, can demasculinize males in anxiety and depressive-like behaviours, and alters the expression of estrogen receptors in the medial amygdala. However, perinatal BPA administration did not alter the survival or soma size of motor neurons controlling penile musculature. Chronic administration during adulthood did reduce soma size in both sexually dimorphic and monomorphic motor neurons, suggesting a non-androgenic mechanism of action. The implication of these data on policy surrounding human exposure to BPA is discussed.
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Thesis advisor: Watson, Neil
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