The estrogens are synthesized by the action of the enzyme aromatase on androstenedione or testosterone (Fig. 25.5). They are normally produced in relatively large quantities in the ovaries and the placenta, in lower amounts in the adrenal glands, and in trace quantities in the testes. In post-menopausal women, most estrogens are synthesized in adipose tissue and other nonovarian sites. About 50 to 350 /g/d of estradiol are produced by the ovaries (especially the corpus luteum) during the menstrual cycle. During the first months of pregnancy, the corpus luteum produces larger amounts of estradiol and other estrogens; the placenta produces most of the circulating hormone in late pregnancy. During pregnancy, the estrogen blood levels are up to 1,000 times higher than during the menstrual cycle.
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Are Menopause Symptoms Playing Havoc With Your Health and Relationships? Are you tired of the mood swings, dryness, hair loss and wrinkles that come with the change of life? Do you want to do something about it but are wary of taking the estrogen or antidepressants usually prescribed for menopause symptoms?