Testosterone blood

SHARPE R M, MARTIN B, MORRIS K, GREIG I, MCKINNELL, MCNEILLY A S, WALKER M (2002) Infant feeding with soy formula mflk effects on the testis and on blood testosterone levels in marmoset monkeys during the period of neonatal testicular activity. Human Reproduction. 17 1692-1703. 

A 19-year-old woman has been referred to an endocrinologist by her gynecologist because of delay in the initiation of her menstrual periods. Physical examination reveals underdeveloped breasts, an enlarged clitoris (rudimentary penis), and the presence of small masses within the labia majora. Blood testosterone is in the normal range for males and a chromosome spread indicates a karyotype of 46,XY. 

The answer is D. The patient s ambiguous secondary sex characteristics and lack of menstrual activity suggest the possibility of an androgen resistance syndrome. The male karyotype and blood testosterone levels confirm this. This clinical condition might have arisen as a result of steroid 5oc-reductase deficiency or inherited defects in the androgen receptor (testicular feminization). 

In general, ethanol in low to moderate amounts, is relatively benign to most body systems. A moderate amount of ethanol causes peripheral vasodilation, especially of cutaneous vessels, and stimulates the secretion of salivary and gastric fluids the latter action may aid digestion. On the other hand, ethanol consumption in high concentrations, as found in undiluted spirits, can induce hemorrhagic lesions in the duodenum, inhibit intestinal brush border enzymes, inhibit the uptake of amino acids, and limit the absorption of vitamins and minerals. In addition, ethanol can reduce blood testosterone levels, resulting in sexual dysfunction. 

Ryan BC, Vandenbergh JG (2002) Intrauterine position effects. Neurosd Biobehav Rev 26 665-678 Vom Saal FS, Bronson FH (1980) Sexual characteristics of adult female mice are correlated with their blood testosterone levels during prenatal development. Science 208 597-599 Vom Saal FS (1989) The production of and sensitivity to cues that delay puberty and prolong subsequent oestrous cycles in female mice are influenced by prior intrauterine position. J Reprod Fert 86 457 71... 

Studies undertaken to study the role of other endocrine activity in these changes showed that injections of norepinephrine and ACTH decreased the rate of production of testosterone and lowered the plasma level. Injections of cortisone alone had no effect on blood testosterone levels (C2). 

Bremner WJ, Vitieho MV, Prinz PN. Loss of circadian rhythmicity in blood testosterone levels with aging in... 

Method for the Determination of Blood Testosterone on the Gas Chromatograph Tsvet" with a Constant Recombination Rate Detector Probl. Endokrinol. 24(5) 48-52 (1978) CA 90 2560q... 

Poly(dimethylsiloxane) has been used to deliver steroid hormones to animals since the 1960 s and commercial poly-(dimethylsiloxane) based delivery systems for estradiol and progestins are currently available. Studies were conducted with androgens to develop poly(dimethylsiloxane) delivery systems that would maintain relatively constant blood testosterone concentrations in ruminant females for six months. All androgens tested passed through the poly(dimethylsiloxane) in vivo at rates proportional to surface area and increased blood testosterone concentrations relatively proportionally to the secretion rate. Implants with testosterone propionate incorporated in poly(dimethylsiloxane) (1) maintained relatively constant blood testosterone concentrations in vivo for six months and maintained more constant blood testosterone concentrations than commercially available implants (nonpoly (dimethylsiloxane) containing testosterone propionate, (2) evoked an anabolic effect in heifers, (3) maintained male sexual behavior in female ruminants and (4) prenatally andro-genized female ruminants. The poly(dimethylsiloxane) implants not only facilitated therapy but also enhanced efficacy and in some cases eliminated side effects. 

Table 1. Implant length and dosage of tesosterone esters required to elevate blood testosterone concentrations to 1.0 ng/ml.

Since silicone implants containing testosterone propionate were demonstrated to maintain relatively constant blood testosterone concentrations they have been used in several studies to evoke various biological responses. Three such responses are (1) the induction of and maintenance of male sexual behavior, (2) an anabolic effect and (3) prenatal androgenization. 

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