Endocrine Abstracts

Bisphenol A (BPA) is a byproduct of polycarbonate plastic widely present in food containers. BPA is historically a known endocrine disruptor and due to its oestrogen agonist activity, BPA consumption is associated with hypothyroidism and reproductive disorder. Recent studies have shown that oestrogen antagonised GH actions. Since BPA has oestrogen agonist activity, the effect of BPA exposure on GH activity has not yet been investigated.

Aim: To study the in vivo effect of acute/chronic consumption of BPA on long body growth and in vitro effect of BPA on cellular GH signalling.

Method: CD-1 mice treated with BPA (1.75 mM orally) for 3 months starting from weaning (day 20). Body weight, tail length, and tibia length were monitored weekly. Liver tissue were collected 15 min after injection of GH or PBS.

Results: Mice given BPA in drinking water showed significant reduction in body weight from days 30 to 60 compared to control littermate. However, as result of catch-up growth, the BPA-treated mice weight became similar to control after day 60. Similar changes were observed in tibia length in which mice treated with BPA had significantly shorter tibia on days 30–50 and started to rise. Chronic treatment of BPA increased expression of SOCS2, which is a known cellular inhibitor of GH signalling.

Conclusion: In humans, there is a dramatic decrease in longitudinal bone growth, which begins during intrauterine life and is interrupted briefly at puberty. Here we found for first time that exposure to BPA, a plastic byproduct, interrupt linear growth with downregulation of GH signalling and mice exposed to BPA exhibit supranormal linear growth phenomenon known as catch-up growth. Further investigation is need to study the effect of BPA on the metabolic action of GH specially those related to body fat content and impact on increasing world epidemic of obesity.