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Abstract :
[en] The increasing presence of endocrine disruption chemicals (EDCs) has been link with a reduction in fertility rate and alterations of pubertal timing. Bisphenol A (BPA) is a ubiquitous EDC used in the manufacture of polyvinyl chloride (PVC) and epoxy resins that we can find in food containers and plastics. Our previous studies have shown that an early postnatal exposure to a low dose of BPA disrupts sexual maturation and pubertal timing. However, its long-term and adult effects on fertility have not yet been studied.
Daily s.c injections of BPA were administered for 15 days to 1 and 90 day-old female Wistar rats at two different doses: a low dose of 25ng/kg/d and a high dose of 5mg/kg/d. The early postnatal exposure to both BPA doses produces a decrease in the percentage of female with a regular cycle characterized by a decrease on the time spend in proestrus (BPA-25ng 13,6±3,4; BPA-5mg 12,2±3,1%; OIL 18,7±3,2%). During exposure at adulthood, both doses caused a disruption of the estrous cycle characterized by a significant decrease in the average time spent in proestrus (BPA-25ng 18,9±2,2%; BPA-5mg 16,9±1,3%; OIL 23,3±0,9%). This effect was We also observed a disruption of folliculogenesis characterized by a significant decrease of antral follicles (BPA-25ng 21,4±2.1%; BPA-5mg 20,94±2%; OIL 35,6±1,6%) and increase of atretic follicles (BPA-25ng 24,2±3,9%; BPA-5mg 26,2±6,3%; OIL 15,5±0,8%). The exposed females showed a regular cycle one month after the last dose of BPA.
In conclusion, both BPA doses have been found to produce a disruption of oestrus cycle and folliculogenesis depending on the window of exposure. While BPA produces persistent effects after early postnatal exposure, exposure during adulthood appears to cause activational, non-persistent alterations.
