Urine estrogens

Since dietary cereals are low in sulfur-containing amino acids, they produce an alkaline urine which favors the retention of bone minerals. In post-menopausal women, there appears to be some interaction between the diet and the effect produced by estrogens on bone mineral content (28). 

Although estrone and estradiol (26) have both been isolated from human urine, it has recently been shown that it is the latter that is the active compound that binds to the so-called estrogen receptor protein. Reduction of estrone with any of a large number of reducing agents (for example, any of the complex metal hydrides) leads cleanly to estradiol. This high degree of stereoselectivity to afford the product of attack at the alpha side of the molecule is characteristic of many reactions of steroids. 

Many systemically administered estrogen products are available in the United States, but conjugated equine estrogens (CEEs), prepared from the urine of pregnant mares, is the most widely prescribed. Transdermal estrogen preparations are also available and usually are prescribed for patients who experience adverse effects, elevated triglycerides, or liver function abnormalities while taking an oral product. Transdermal preparations also have a lower incidence of venous thromboembolism than oral preparations.9... 

Exemestane is an irreversible aromatase inactivator that binds to the aromatase enzyme to block the production of estrogen from androgens. Exemestane is absorbed rapidly after oral administration, with a terminal half-life of 24 hours. The drug is eliminated primarily by the liver and feces, with less than 1% of the dose excreted unchanged in the urine. Exemestane is indicated for the treatment of advanced breast cancer in postmenopausal women who have had disease progression following tamoxifen therapy. Side effects include hot flashes, fatigue, osteoporosis/bone fractures, and flulike symptoms. 

Because estrogenic mycotoxins usually occur at microgram per kilogram (pg/kg) levels there is special interest in analytical procedures for reliable detection of zearalenone and its metabolites between 10 and 100 pg/kg. In response to the risk of a great economic loss to the industry and the threat to human health as a result of exposure to zearalenone, several methods have been developed for the quantification of zearalenone and its metabolites in different foods, feeds, animal tissues, blood and urine. Detailed reviews have been given by Steyn et al. 1991 Betina 1993 Frisvad and Thrane 1993 Scott 1993 Steyn 1995 and Lawrence and Scott 2000. The determination of zearalenone in cereals can be divided into five steps grinding of the sample, extraction of the sample, clean-up, separation and detection. 

Sex differences in olfactory performance have been described for many mammals, implying hormonal differences. In domestic cats, as in other species, males typically perform flehmen in response to conspecific urine. But spayed females can be stimulated to show flehmen by administering testosterone. If paired with estrogen-treated females, they frequently inspect the genital area of the female partner and subsequently exhibit flehmen. Males flehmen in 80% of the time to either female or male urine that is applied to the naso-oral surface. Testosterone-treated females flehmen to 90% of the male urine samples, and to 70% of those from females (Hart and Leedy, 1987). 

Determination of Estrogens, Androgens, Progesterone, and Related Steroids in Human Plasma and Urine Ian E. Bush... 

Estrogens - Ethinyl estradiol is rapidly absorbed with peak concentrations attained in 1 to 2 hours. It undergoes considerable first-pass elimination. Mestranol is demethylated to ethinyl estradiol. Ethinyl estradiol is approximately 97% to 98% bound to plasma albumin. Half-life varies from 6 to 20 hours. It is excreted in bile and urine as conjugates, and undergoes some enterohepatic recirculation. 

Therapeutically, gonadotropins are used to induce ovulation in infertile women. The antiestrogens clomiphene (5.37) and tamoxifen (5.38) are also used for this purpose since they counteract the ovulation-inhihitory effect of estrogens. Pregnancy tests depend on the presence of an increased hCG concentration in the urine after fertilization. 

Natural estrogens are inactive orally due to rapid metabolism in liver. Synthetic estrogens are well absorbed after oral administration as well as by transdermal application. Estradiol is metabolized to estrone and estriol. All these are conjugated and excreted in urine and bile. Synthetic... 

Three forms of purified FSH are available. Urofollitropin, also known as uFSH, is a purified preparation of human FSH that is extracted from the urine of postmenopausal women. Virtually all the LH activity has been removed through a form of immunoaffinity chromatography that uses anti-hCG antibodies. Two recombinant forms of FSH (rFSH) are also available follitropin alfa and follitropin beta. The amino acid sequences of these two products are identical to that of human FSH. They differ from each other and urofollitropin in the composition of the carbohydrate side chains. The rFSH preparations have a shorter half-life than preparations derived from human urine but stimulate estrogen secretion at least as efficiently and, in some studies, more efficiently. The rFSH preparations are considerably more expensive. 

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