Estrogen vital for male fertility
Science Update reports a 'Letter to Nature', R A Hess, D Bunick, K-H Lee, J Bahr, J A Taylor, K S Korach & D B Lubahn, describe an important role for estrogens in the male reproductive system. As we all know, estrogen is stereotyped as the 'female' hormone, and testosterone as the 'male'. Both hormones are present in both sexes and sexual distinctions are due to differences in concentrations and differing effects on hormone receptors. In males, estrogen is present in low concentrations in blood, and it is already known that male reproductive tissues express estrogen receptors, but their role has remained unclear. The authors point out that estrogen concentration "can be extraordinarily high in semen, and as high as 250pgml-1 in rete testis fluids, which is higher than serum estradiol in the female." The authors have demonstrated evidence of a physiological role for estrogen in male reproductive organs. The immature sperm travel in fluid, into a collecting area and onwards into a body called the epididymis. As this dilute sperm solution enters the epididymis, about 90 per cent of the fluid is reabsorbed, regulated by a particular estrogen hormone, estradiol. Disruption of this essential function causes sperm to enter the epididymis diluted, rather than concentrated, resulting in infertility. Moreover, the chemicals and nutrients that sperm need to mature are also diluted. Hess and his team say that their "discovery is important given recent concerns over reported declines in human sperm counts and speculation that environmental estrogens might be a cause of this."
Bland, J.,(1999) About Gender: Estrogen vital for male fertility.
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Last amended 10.07.99