Newly Found Estrogen Role In Males Might Lead To Contraceptive For Men.

2001 DEC 6 - (NewsRx.com & NewsRx.net) -- Newly found estrogen role in males might lead to contraceptive for men

Researchers tapping into the estrogen pathway that regulates fertility in males have found two independent roles of the hormone, and they may have uncovered a new approach for developing a male contraceptive.

In a paper in the Proceedings of the National Academy of Science USA, University of Illinois scientists report that estrogen regulates fluid reabsorption in the male reproductive tract by triggering a protein involved in sodium transport. They also detail in the paper - published in the online PNAS Early Edition on November 6, 2001 - that estrogen sustains the morphological architecture of the efferent ductules.

"We were not expecting this second role of estrogen," said Rex A. Hess, a professor of reproductive biology and toxicology at the University of Illinois College of Veterinary Medicine. "This structure-sustaining role appears to be independent of estrogen's molecular function of regulating ion transport. This tells us that estrogen is important for the expression of other genes with distinct physiological and morphological functions."

Hess and colleagues had documented in 1997 that estrogen was vital for fluid reabsorption during the transfer of sperm in fluid from the testis through the efferent ductules to the epididymis, where sperm matures and is stored. The PNAS paper provides a molecular picture of what estrogen does.

Efferent ductules are small tubes that produce concentrated semen. In a series of experiments using mice lacking the estrogen receptor or proteins thought to be regulated by estrogen, the scientists showed that when sodium transport did not occur, excess fluid diluted the sperm, leaving mice infertile. However, when estrogen ...