ER agonists regulate androgen biosynthesis in Leydig cells. Incubation of mature rat Leydig cells, from 90-day old rats, with estrogenic chemicals, i.e., bisphenol A (BPA)(A), the synthetic estrogen diethylstilbestrol DES (B) and a biologically active metabolite of the pesticide methoxychlor (HPTE)(C), caused an inhibitory effect on androgen biosynthesis albeit at different doses. Using RT-PCR, ERβ was not detected in these cells, implying that inhibitory effects were ERα-mediated (ref. 89). Copyright 2004, The Endocrine Society.