Bisphenol A Modifies the Regulation Exerted by Testosterone on 5α-Reductase Isozymes in Ventral Prostate of Adult Rats

Abstract EN

The development, growth, and function of the prostate gland depend on androgen stimulation.

The primary androgen in prostate is 5α-dihydrotestosterone (DHT) which is synthesized from circulating testosterone (T) through the action of 5α-reductase (5α-R).

Although 5α-R occurs as five isozymes, only 5α-R1 and 5α-R2 are physiologically involved in steroidogenesis.

The endocrine disruptor bisphenol A (BPA) alters sexual organs, including the prostate.

Our previous findings indicated that BPA decreased the expression of 5α-R1 and 5α-R2 in rat prostate but also circulating T.

Thus, it is unclear whether BPA exerts this effect on 5α-R isozymes by reducing circulating T or by any other mechanism.

In this study, we examine the effects of short-term exposure to BPA at doses below 25 μg/Kg/d and above 300 μg/Kg/d of the TDI on mRNA levels of 5α-R1 and 5α-R2 in prostate of adult castrated rats supplemented with T to achieve constant circulating T levels.

mRNA levels were measured by absolute quantitative RT-PCR, T levels by RIA, and DHT levels by ELISA.

Our results indicated that in castrated rats treated with T BPA at the two doses studied significantly decreased the mRNA levels of both 5α-R isozymes in a dose-dependent manner without modifications in circulating T.