Estrogen: Not just produced by the ovaries
by Jordana Lenon
Excerpt: “Discovering that the hypothalamus can rapidly produce large amounts of estradiol and participate in control of gonadotropin-releasing hormone neurons surprised us,” says Ei Terasawa, professor of pediatrics at the UW School of Medicine and Public Health and senior scientist at the Wisconsin National Primate Research Center. “These findings not only shift the concept of how reproductive function and behavior is regulated but have real implications for understanding and treating a number of diseases and disorders.”
My comment: It is great to see things like this reported, since our 1996 attempt to call attention to the information on neurosteroids failed. Why were these researchers surprised? We reported this information about neurosteroids 17 years ago in our Hormones and Behavior review article.
“Relatively new, however, is the realization that various portions of the CNS itself can produce steroids and can do so independently of the gonads and adrenals (Baulieu and Robel, 1990; Roselli, 1995). These “neurosteroids” (steroids produced by neurons) have been reported in the fetal brain, suggesting localized organizational effects (Kabbadj, el-Etr, Baulieu, and Robel, 1993). Activational effects in sexual behavior have also been shown for neurosteroids (Genazzani, Palumbo, de Micheroux, Artini, Criscuolo, Ficarra, Guo, Benelli, Bertolini, Petraglia, and Purdy, 1995), even at intermediate levels of a steroid conversion sequence (Kavaliers and Kinsella, 1995).
Though neurosteroids research is relatively new, certain findings already are important. For instance it is now known that (i) the enzymes that produce neurosteroids are transcribed from the same genes that produce gonadal and adrenal steroids (Compagnone, Bulfone, Rubenstein, and Mellon, 1995b; Mellon and Deschepper, 1993); (ii) transcription regulation for neurosteroidal enzymes is different from gonadal and adrenal regulatory processes (Zhang, Rodriguez, and Mellon, 1995); (iii) within discrete brain nuclei, some subareas differ with regard to utilization of neuro- and nonneurosteroids (Compagnone et al., 1995a; Roselli, 1995); and (iv) even early stages in the neurosteroid route from cholesterol to various end-product steroids affect sexual perceptions and behavior (Kavaliers and Kinsella, 1995).”
I’m convinced that we provided too much experimental evidence for support when some people were clinging to theory. Many people cling to their theories until an information overload of accurate representations of biological facts forces them to acknowledge the paradigm shift occurred. They must then privately acknowledge it and proceed to “catch up.” Note, you never see anyone claim that they were not surprised by such dramatic findings, even though they should have known all along that their findings were perfectly predictable because conserved molecular mechanisms are clearly involved that link microbes to man.
Unfortunately, the possibility that human pheromones could be used to stimulate the release of estradiol and relieve the symptoms of menopausal “hot flashes” has still not been examined. When women who have suffered from, or are now suffering from, severe symptoms of estrogen withdrawal find out that researchers have ignored research that could have helped them, I suspect that much ‘hate mail’ will be generated.
