Estrogens growth

Testosterone promotes muscle growth deepening of the voice the growth of body hair and other male secondary sex characteristics Testosterone is formed from cholesterol and IS the biosynthetic precursor of estradiol the principal female sex hormone or estrogen Estradiol is a key substance m the regulation of the menstrual cycle and the reproductive process It is the hormone most responsible for the development of female secondary sex characteristics... 

Increased hormonal levels have resulted in better mminant animal performance. Fstrogen-containing compounds, eg, zearalenone [17924-92-4], 18 22 5 available to improve growth and feed efficiency. These estrogens are given as ear implants. Melengestrol acetate [2919-66-6] (MGA),... 

NaturaHy occurring and synthetic estrogens and androgens have been extensively and safely used to improve efficiency and carcass composition ia growing beef catde in the United States since the early 1950s. Several anaboHc steroid implants have been approved for use in beef catde in the United States, but only one, zeranol [55331-29-8] is approved for use in lambs. Anabolic steroids are not used for growth regulation in swine or poultry (see Steroids). 

WS-7528 [132147-69-4][VI] a nonsteroidal estrogen, is an isoflavone which has been isolated from Streptomjces sp. No. 7528 and is an estrogen agonist. It inhibits [3ff]-estradiol binding to its receptor in rat uterine cytosol at an inhibitor for 50% of the rats tested (IC q) concentration of 5.7 nM. It also induces the growth of estrogen-dependent human breast cancer cell line MCE-7 (7). 

Estrogens coordinate the systemic response during the ovulatory cycle, including the growth and maintenance of the reproductive tract, pituitary, breasts, and other tissues. Estrogens are also responsible for maturation of the skeleton and development of female secondary sex characteristics when females enter puberty. The other important functions of estrogens include modulation of many metaboHc processes (76). 

Estrogens stimulate cellular proliferation, induce RNA and protein synthesis of uterine endometrium and the fibrous connective tissue framework for ovaries, and increase the size of the cells. This effect leads to the growth and regeneration of the endometrial layer and spinal arterioles, and increase in the number and size of endometrial glands. Under the influence of estrogen, vaginal mucosa becomes thicker, as cervical mucus becomes thinner (85,86). 

Prosta.te Ca.ncer, Estrogen has an inhibitory effect on the prostate in addition to its suppression of gonadotropin secretion by the pituitary. The three- and five-year survival rates in prostate cancer patients with metastatic disease improved when treated with DES (7) alone or along with castration. However, DES does not improve the survival rates in patients whose carcinoma is confined to the prostate. Small doses of DES (1 mg/d) appear to retard prostate cancer growth and could reduce the cardiovascular complications associated with larger doses (5 mg/d) (135) (see... 

Many stilbenelike thiophene compounds have been prepared for a study of estrogenic activity, especially by Buu-Hoi et al. Thiophene derivatives of nonhydroxylated stilbene types showed no significant activitywhereas weak estrogenic activity was found in 5-acetyl-, 5-propionyl-, and 5-benzoyl-2-(-stilbenyl)thiophene. 1-Bromo-l,2-diphenyl-2-(5-bromo-2-thienyl)ethylene (258) was found to inhibit body growth and to produce extensive testicular atropy in male rats. A thiophene analog of estrogenic isoflavones (259)... 

Cells from tissues associated with primary and secondary sexual characteristics are under particular endocrine control. Sex hormones determinethe growth, differentiation, and proliferation of such cells. When a tumor develops in such tissues, it is sometimes hormone dependent and the use of anti hormones removes the impetus for the tumor s headlong growth. Many nonsteroidal compounds have estrogenic activity diethylstilbest-jrol (81) may be taken as an example. Certain more bulky an-... 

Breast cancer is cancer of the breast tissues. The major part of this cancer in women is dependent on the female sex hormones for their growth. An estrogen antagonist can therefore be used in the treatment of breast cancer to limit the growth of the tumor. 

Estrogens mainly affect the growth and maturation of the female reproductive system and the maintenance... 

The estrogens are secreted by the ovarian follicle and in smaller amounts by the adrenal cortex. Estrogens are important in the development and maintenance of the female reproductive system and the primary and secondary sex characteristics. At puberty, they promote growth and development of the vagina, uterus, fallopian tubes, and breasts. They also affect the release of pituitary gonadotropins (see Chap. 50). 

Other actions of estrogen include fluid retention, protein anabolism, thinning of the cervical mucus, and the inhibition or facilitation of ovulation. Estrogens contribute to the conservation of calcium and phosphorus, the growth of pubic and axillary hair, and pigmentation of the breast nipples and genitals. Estrogens also stimulate contraction of the fallopian tubes (which promotes movement of the ovum), modify the physical and chemical properties of the cervical mucus, and restore the endometrium after menstruation. 

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