17/3-Estradiol testosterone metabolite

Steroid hormones form a group of pollutants that includes natural hormones such as estradiol, testosterone, and their metabolites as well as several synthetic analogues. Steroid hormones used as growth promoters have already been found in water and sediments (Lai et al. 2000 Thorpe et al. 2003), and their adsorption properties on earth materials have been considered. Lee et al. (2003) report batch experiments where simultaneous sorption of three hormones (17- 3-estradiol, 17-a-ethyl estradiol, and testosterone) on four midwestem U.S. soils and a freshwater sediment were performed. Apparent sorption equilibria were reached within a few hours. Sorption isotherms generally were linear for the chemicals studied on one of these soils (Drummer soil), ranged from 23.4 to 83.2 L kg and log ranged... 

In vivo studies in animals suggest that endosulfan may disrupt normal reproductive hormone levels in male animals, but that it is not an endocrine disrupter in females. Persistent depressed testicular testosterone was seen in male rats after intermediate duration oral exposures to endosulfan. In ovariectomized female rats, orally administered endosulfan did not induce normal development of female reproductive tissues, and in female mice and immature female rats, acute parenteral exposure to endosulfan did not affect several endocrine-related end points. In vitro studies have evaluated endosulfan for estrogen receptor (ER) and cytosolic protein binding affinity, ER-mediated reporter gene expression, estrogenic induction of cell proliferation, and alteration of relative abundance of active estradiol metabolites. Overall, in vitro evidence in favor of endosulfan estrogenicity indicates relatively weak potency compared to 17[3-estradiol. Apparently contradictory results were reported in different... 

The U.S. Food and Drug Administration policy is based on the conclusions of the Joint FAO/ WHO Expert Committee on Food Additives (JECFA). In its Thirty-Second Report (1988), it concluded, on the basis of its safety assessment of residues of estradiol-17/3, progesterone, and testosterone, and in view of the difficulty of determining the levels of residues attributable to the use of these hormones as growth promoters in cattle, that it was unnecessary to establish an acceptable residue level. As to trenbolone acetate (TBA), a synthetic steroid with anabolic properties, JECFA concluded that its safety assessment could be based on establishing the no-hormonal-effect level. It therefore recommended a maximum residue level of 2 /zg/kg for /3-tren-bolone in meat and of 10 /xg/kg for a-trenbolone in liver on the basis of a daily intake by a 70-kg person of 500 g of meat. /3-Trenbolone is the major metabolite in muscle. For zeranol, an acceptable residue level of 10 /xg/kg for bovine liver and 2 /zg/kg for bovine muscle was established. 

The step-by-step synthesis of the steroid hormones pregnenolone and progesterone from cholesterol (C27) was presented in chapter 20 (see fig 20.22). Note that pregneno-lone (C2i) and progesterone (table 20.4) (C2 ) are intermediates in the biosynthesis of all of the major adrenal steroids, including cortisol (C2i), corticosterone (C21), and aldosterone (C21). The same two compounds are intermediates in the synthesis of the gonadal steroid hormones, testosterone (C,9) and 17/3-estradiol (CI8). Because the synthesis of all these hormones follows a common pathway, a defect in the activity or amount of an enzyme along that pathway can lead to both a deficiency in the hormones beyond the affected step and an excess of the hormones, or metabolites, prior to that step. 

Metabolites and substrates (urea, triglycerides, bili-rubine, lactate), enzymes (the measurands are the enzyme activities), hormones (aldosterone, estradiol, es-triol, testosterone, thyroxin), drugs (theophylline, digoxin, digitoxin), total proteinAs far as possible, isotope dilution mass spectrometry is used for the primary measurements in both institutes (e.g. [4]). 

Since the neutral molecules of steroid hormones and metabolites are not easily ionized under either APCP or ESI+/ modes, LC-MS/MS is less sensitive when used directly in either APCP or ESI+/ modes, with LOQs at ng/mL level as shown in Table 4 [20, 21, 52], It has been observed that estrone, 16a-hydroxyestrone, 2-methoxyestrone, 4-methoxyestrone, and 2-hydroxy-3-methoxyestrone are sensitive to APCI+ mode, while 2-hydroxyestrone and 4-hydroxyestrone are sensitive to APCI- mode, and even more sensitive to ESI mode [29], Estrone, estradiol, estradiol, and estriol are sensitive to ESI" mode, and testosterone is sensitive to ESP mode [76, 77], Similarly, estrone and estradiol are sensitive to APPI" mode, and testosterone is sensitive to APPI+ mode with LOQs in a range of 1.5-10 pg/mL [22], which are comparable with those steroid hormones and metabolites derivatized with hydroxylamine or dansyl chloride, and detected under ESP mode [2, 8],... 

Metabolism E. are formed in the Graafian follicles of the ovaries and in the corpus luteum, and during pregnancy also in the placenta they also occur in small amounts in the male organism. Estrone is principally biosynthesized from androst-4-ene-3,17-dione, the 17-dehydro product of testosterone, by an aromatase. Estradiol is metabolized in the liver to 2-methoxyestrone via estrone. Estriol is also formed by side reactions. Both metabolites are excreted by the kidneys. Equilenin and equilin are also metabolic excretion products of estrogens. 

Srinivas and Srinivasulu (1993) found that heulandate layers developed with carbon disulfide-pyridine (1 1) were effective for the separation of steroid hormones,—dehydroepiandrosterone could easily be separated from mixtures of cholesterol and estradiol benzoate or testosterone phenylpropionate, and testosterone could be separated from mixtures of cholesterol and testosterone phenylpropionate or estradiol benzoate. Likewise, estradiol could easily be separated from mixtures of cholesterol and estradiol benzoate. Daeseleire et al. (1994) applied HPTLC and GC/MS for the detection of anabolic steroids used as growth promoters in illicit cattle fattening within the European market. Agrawal et al. (1995) developed a sensitive, reliable, and rapid silica gel TLC method for the separation, identification, and quantification of stereospecific androgen metabolites. 

The primary and most important androgen is testosterone. In the adult male, its active metabolite dihydrotestosterone supports spermatogenesis for reproduction as well as maintaining muscle mass and fat distribution. Estrogens are associated with development of female secondary sex characteristics and comprise of estrone, estradiol, and estriol. Steroid hormones are not exclusively gender specific and have important roles in both males and females. 

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