Testosterone adrenal, production

The saturated Cai compounds are then either conjugated with glucuronic acid and appear in urine as the glucuronides, or they are further broken down. The side chain is split off particularly easily from 17-hydroxy compounds. The products are 17-keto steroids, androsterone, etiocholanolone, and. others, which are also excreted as glucuronides (more rarely as sulfates). The amount of 17-keto steroids in urine can be estimated easily with Zimmermann s color reaction it is useful for the diagnosis of adrenal cortical activity. One should be aware, however, that only a part of the corticosteroid excretion is measured, together vith testosterone inactivation products. Normally, about 10-20 mg per day of 17-keto steroids are excreted. 

Significant amounts of estrogens are produced by the peripheral aromatization of androgens. In human males, the peripheral aromatization of testosterone to estradiol (Ej) accounts for 80% of the production of the latter. In females, adrenal androgens are important... 

Isolated cells from adrenal and testes held in media containing 0.065, 0.65, or 6.5 mg/kg for 2 h No effect at lowest doses. High dose caused decreased survival of cells from both organs and reduced testosterone production 23... 

Endocrine effects Statins interfere with cholesterol synthesis and lower circulating cholesterol levels and, as such, might theoretically blunt adrenal or gonadal steroid hormone production. Small declines in total testosterone with no commensurate elevation in LH have been noted with the use of fluvastatin. Pravastatin showed inconsistent results with regard to possible effects on basal steroid hormone levels atorvastatin, lovastatin, rosuvastatin, and simvastatin did not reduce basal plasma cortisol concentration or basal plasma testosterone concentration or impair adrenal reserve. Appropriately evaluate patients who display clinical evidence of endocrine dysfunction. Exercise caution when administering HMG-CoA reductase inhibitors with drugs that affect steroid levels or activity, such as ketoconazole, spironolactone, and cimetidine. 

Male and female hormones are produced primarily in the gonads. Androgens are synthesized in the testes in the male. In the female, the ovaries are the principal sites of estrogen and progestin production. As discussed in Chapter 29, small amounts of sex-related hormones are also produced in the adrenal cortex in both sexes, which accounts for the fact that small amounts of hormones of the opposite sex are seen in females and males that is, low testosterone levels are seen in females, and males produce small quantities of estrogen. However, under normal conditions, the amounts of sex-related hormones produced by the adrenal cortex are usually too small to produce significant physiologic effects. 

Overall, other adrenal androgens also show a progressive decrease in urinary excretion in both men and women. Thus, the mean 17-ketosteroid urine levels of elderly people are about 50% of those in young adults. This is primarily secondary to decreased dehydroepiandrosterone (DHEA) and androsterone production. In men, about one-third of the daily 17-ketosteroids are of testicular origen, the remainder being mainly from the adrenals. Androstenedione is a prehormone for testosterone. 

The liver is the most important area for (he production of cholesterol and bile acids. The ovaries are the most important sources of estrogen and progesterone (progesterone is produced in the corpus luteum of the ovary). The testes are the major site of androgen production, testosterone especially. The adrenal cortex produces the mineralocorticoids and glucocorticoids, and the androgens dehydroepiandrosterone and androstenedione. 

Metabolism studies. GC-MS is a powerful technique for following and identifying the metabolic products from the in vitro incubation of tissue preparations with steroid substrates. Examples of such studies include the 16a-hydroxylation of 18-hydroxydeoxycorticosterone by human adrenal gland [254], the eiromatization of 3jS,15, 16 -trihydroxy-5-androsten-17-one by placental homogenates [255], and the demonstration of 1/3, 12/3, 6a and 6/3 hydroxylase enzyme activities in microsomal preparations of human foetal hepatic tissue [256]. In the latter study, testosterone was used as substrate and in addition to the hydroxylated metabolites isolated, several other testosterone derivatives indicated the presence of 3a, 3/3 and 17/3-hydroxysteroid oxidoreductase in the adrenal gland preparation. 

ANDROGENS are predominantly male steroid sex hormones that act directly to stimulate the development of male sex organs, and male secondary sexual characteristics, by acting at receptors on target tissues. Production is under the control of the pituitary hormone, corticotrophin. In men, androgenic steroids are produced primarily by the testes, and the main form is testosterone. However, in both men and women, androgens are also produced by the adrenal glands, and in women small quantities are also secreted by... 

Several en2yme defects will cause a deficiency of testosterone production during fetal development. These include 20a-hydroxylase (cholesterol 20,22-desmolase) deficiency, which prevents conversion of cholesterol to pregnenolone and results in congenital lipoid adrenal hyperplasia, so named because the adrenals are large and filled with lipoid... 

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