To: Proton who wrote (12053 ) 12/4/1997 1:16:00 PM From: Henry Niman Read Replies (2) | Respond to of 32384
Here's more good news for LGND: L O N D O N, Dec. 3 - Estrogen has always been considered the female hormone, but medical research shows it plays an important role in male fertility. In a report in the scientific journal Nature, doctors at the University of Illinois said they've discovered that estrogen helps keep sperm strong. Without the hormone, sperm becomes diluted, which can result in infertility. "We produce evidence of a physiological role for estrogen in male reproductive organs," said Rex Hess, who led the research team. Their experiments on mice showed that estrogen regulates the reabsorption of luminal fluid in a tube in the testicle. If the fluid is not absorbed, the sperm will be diluted rather than concentrated, which can cause infertility. Using infertile male mice which lacked a form of estrogen receptor that reacts to the hormone, Hess and his team found that instead of reabsorbing the fluid, the mice secreted it within the testes. The build-up of pressure from the fluid could impair sperm production. Hess said the data suggested that estrogen deficiency or insensitivity in humans might also result in an accumulation of fluid and subsequent atrophy of the testes. One of Many Roles Richard Sharpe of the Medical Research Council Reproductive Biology Unit in Edinburgh said the finding was probably just the first of many roles for estrogen in males because there are estrogen receptors, which respond to the hormone, in the pituitary gland, brain, bone, skin and heart. In an accompanying article in Nature, Sharpe said the next step would be to unravel the biochemical details of fluid resorption. "We should also expect some twists to this story, such as evidence that the estrogen that controls fluid resorption may come from the sperm themselves and that, under some circumstances, estrogens may inhibit rather than promote fluid resorption," he said. He described the Illinois study as a "turning point." "It provides clear evidence that estrogens do something very concrete in the male reproductive system. It will force us to start asking the broader question-what are they doing at other sites," he said in an interview. Raises Questions Knowledge of the biological role of estrogen in male reproduction may also shed new light on the theory that environmental estrogens in organic pollutants, ranging from pesticides to industrial chemicals, are the cause of diminishing sperm counts. A recent report from the United States showed that sperm counts are falling faster than most medical experts had thought. The re-analysis of 61 studies by researchers at the California Department of Health confirmed significant sperm declines in Europe and the United States. But Sharpe said there's still no evidence that environmental estrogens in humans have any effects on any aspect of health. "It is a possibility (still unproved) that exposure of the developing human male to such chemicals might have contributed to reported adverse changes-reduced sperm counts, genital anomalies and testicular cancer-in male reproductive health," he said. "All this study does is say this is the first of many functions of estrogen in the male which are potential targets for environmental estrogens."