Testosterone hormonal effects

The synthesis and degradation of muscle proteins are regulated by hormones. Cortisol leads to muscle degradation, while testosterone stimulates protein formation. Synthetic anabolics with a testosterone-like effect have repeatedly been used for doping purposes or for intensive muscle-building. 

At high doses, ketoconazole causes a clinically significant reduction in testosterone synthesis and blocks the adrenal response to corticotropin. Gynecomastia, impotence, reduced sperm counts, and dimiiushed libido can occur in men, and prolonged drug use can result in irregular menses in women. These hormonal effects have led to the use of ketoconazole as a potential adjunctive treatment for prostatic carcinoma. 

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. 

As mentioned before, circulatory levels of testosterone also effect HPTA function, so I should not list it as a characteristic unless I also list pretty much every other sex-hormone as well. 

I realize that this is a side track issue, but relevant all the same. Cycle protocols were an approach intended to facilitate optimal growth of muscle tissue. Remember there are two main muscle fiber types Type I, which is endurance orientated, and Type II which is strength orientated. Type "Ha", "Hb", and Type "He" are responsible for most musculature size and have the greatest potential for growth. Testosterone increases the number of Type II fibers at the expense of the Type I transformation. Growth hormone, Insulin, IGF-1, and thyroid hormones effect growth and hyperplasia of both fiber types. This should be another key relating to protocols that were utilized and why. 

While legally speaking melatonin is a dietary supplement, biologically speaking it is a hormone. Other types of hormones include estrogen and testosterone. Hormones are known to have major effects on the human body. Only one other hormone can be sold over the counter in the United States. All other hormones require a doctor s prescription. Many other countries do not allow over-the-counter sales of melatonin because it is a hormone and has not been studied well enough to know if it is safe to take. 

The almost universal presence of adenosine 3 , 5 cyclic phosphate (cAMP) as a biologic regulator in microbial and hormone-sensitive animal tissues raises the question of whether this nucleotide might mediate the steroid hormone effect on specific enzyme synthesis. This possibility is made especially attractive because certain enzymes known to be induced by the steroids can also be induced by the cyclic nucleotide. Thus, several enzymes which are induced in the prostate or seminal vesicles by (dihydro) testosterone can also be induced by cAMP (Singhal et al., 1970). Likewise, tyrosine aminotransferase is inducible in embryonic and adult liver by the cyclic nucleotide as well as by the glucocorticoids (Wicks, 1968). 

Implants are small, sterile cylinders of dmg, inserted beneath the skin or into muscle hssue to provide slow absorption and prolonged achon therapy. This is principally based on the fact that such dmgs, invariably hormones, are almost insoluble in water and yet the implant provides a rate of dissoluhon sufficient for a therapeuhc effect. The British Pharmacopoeia (1993) describes one implant, testosterone. The United States National Formulary (1990) also ineludes oestradiol. Implants are made fiom the pure drug into tablet form by compression or fusion. No other ingredient can be included sinee this may be insoluble or toxie or, most importantly, may influence the rate of drug release. 

Sex differences in uptake and metabolism of trichloroethylene have been seen in both humans and animals (see Section 2.8). Studies with male and female rats given various levels of testosterone have implicated this hormone in determining the degree of dermal penetration of trichloroethylene (McCormick and Abdel-Rahman 1991). The mechanism behind this effect is still unclear. 

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