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Progestogens Estrogens

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Effects of Female Sex Hormones


Estrogens promote the development of the female sex characteristics, i.e., the transformation of the Müller ducts into Fallopian tubes, uterus and vagina, as well as the secondary sexual characteristics (e.g., development of the mammary glands and female fat distribution). They require the cooperation of andro-gens in order to stimulate axillary and pubic hair growth. Estrogens also influence the psychological development of women. In sexually mature women estrogens and progestogens have partly opposite actions.

Estrogens promote the proliferation of the uterine mucosa. In the cervix and vagina they reduce the viscosity of the cervical mucus and accelerate the exfoliation of the vaginal epithelium, whose glycogen is broken down by the vaginal flora to lactic acid. The resulting fall in pH stops pathogens from penetrating. Estrogens stimulate the formation of ducts in the mammary glands. They promote protein anabolism and increase the formation of HDL and VLDL. Conversely, they reduce the concentration of low density lipoproteins (LDL), and thus lower the risk of atherosclerosis. On the other hand, estrogens increase the coagulability of blood. Additionally, they raise electrolyte retention in the kidneys as well as the mineralization of the bones via hydroxylation of vitamin D3 and the inhibition of parathyroid hormone (PTH). In children they promote bone growth and maturation and accelerate epiphy-seal fusion.


In the uterus progesterone promotes the maturation and secretory activity of the uterine mucosa and decreases the contractility of the uterine muscle. When estrogen concentration falls at the end of the menstrual cycle, the mucosa is shed (menstruation). In the cervix and vagina progestogens raise the viscosity of cervical mucosa, narrow the cervical orifice, and inhibit fallopian motility. Furthermore, they inhibit the proliferation and exfoliation of vaginal epithelium. They also promote the formation of alveoli in the mammary glands. Proges togens (progesterone and its analogs) raise the body's metabolism and temperature, trigger hyperventilation, and reduce sensitivity to insulin in the periphery. Additionally, they have moderate glucocorticoid and antimineralocor-ticoid (natriuretic) actions. They lower the production of cholesterol and the plasma concentration of HDL and LDL.

Effects of Excess and Deficiency

In excess of female sex hormones (^A2) go-

nadotropin release is inhibited, there is no maturation of the follicles, no regular shedding of the uterine mucosa, and the woman will be infertile. An excess of estrogens can cause thrombosis due to a raised clotting tendency. In children high estrogen concentrations lead to premature sexual maturation and accelerate growth. However, premature epiphyseal fusion may eventually result in short stature. Increased progestogen action causes natriure-sis, a rise in body temperature and hyperventilation, and via insulin resistance it can promote the development of diabetes mellitus.

A deficiency of female sex hormones (^ A3), like their excess, means that a normal menstrual cycle is not possible. In estrogen deficiency the phase of uterine proliferation is absent and the progestogens are not able to bring about maturation; in progestogen deficiency the uterine mucosa does not mature. In both these cases the woman is infertile and there is no menstrual bleeding (amenorrhea). The lack of estrogens also expresses itself in reduced manifestation of the external sex characteristics, in a tendency toward vaginal infections, in osteoporosis, and in an increased risk of atherosclerosis. In children there will be a delayed epiphyseal fusion that, despite slowed growth, may ultimately lead to tall stature.

The reproductive functions of a woman can also be abnormal independently of the sex hormones, for example, due to malformations or disease of the ovaries, fallopian tubes, or uterus.

A. Effects of Female Sex Hormones

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