Sex Hormones

" In women, estrogens and progestogens are the main sex hormones. Estrogens are steroid hormones synthesized from androgens under stimulation of follicle stimulating hormone by the ovaries and in lower concentrations by the liver, adrenal glands, breasts and fat. Action of estrogens is mediated by the estrogen receptor, resulting in various effects on menstrual cycle, sexual characteristics et cetera. Progesterone is also a steroid hormone synthesized from the cholesterol-derived pregnenolone by the ovaries and adrenal glands. It is the precursor of aldosterone and after conversion into 17-hydroxyprogesterone of cortisol and androstenedione, the latter can be converted to testosterone, estrone and estradiol. Progesterone binds to the progesterone receptor and has key effects in the reproductive system and nervous system. Testosterone is in small amounts present in women, but is the main sex hormone in men. Like the other steroid hormones, it is derived from cholesterol. Testosterone exerts its effect through binding to the androgen receptor at one hand and by conversion to estradiol and activation of estrogen receptors at the other hand. It plays a key role in the development of male reproductive tissues such as testes and prostate, it is necessary for normal sperm development and promotes secondary sexual characteristics. Furthermore, testosterone is essential for general well-being . ADH secretion is subjected to circadian rhythms, but also to the menstrual cycle in women. Increased basal and nocturnal ADH concentrations are found in the midfollicular phase of the menstrual cycle; postmenopausal women who take in estrogen will have increased ADH, whereas the combination of estrogen and progesterone lowers the ADH concentrations. High estrogen states decrease baseline plasma-osmolality and sodium by resetting of the osmoreceptors for thirst and ADH release. However, in this situation ADH secretion persists and slightly hypotonic plasma is maintained. Another study suggests that 3beta- 17beta-estradiol (E2) augments osmotic ADH secretion with water retention as a consequence, however, the enhanced fluid retention was mainly based on an increase in renal sodium reabsorption. (An-Sofie Goessaert, Johan Vande Walle, Ayush Kapila and Karel Everaert- Hormones and Nocturia: Guidelines for Medical Treatment?) "

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Last date updated on September, 2024