Adrenal Androgen, Dehydroepiandrosterone DHEA

The adrenal glands play an important role in pubertal development. Termed adrenarche, the maturation of a prominent zona reticularis, the innermost layer of the cortex, begins around age six to eight in girls, resulting in increased secretion of the adrenal androgens, dehydroepiandrosterone (DHEA) and DHEA sulfate (Beckman Feuston, 2003). The rise in these hormones leads to the development of pubic and axillary hair. Recent evidence suggests... 

Adrenocortical steroid hormones have a vast array of biological functions. Cortisol, the primary human glucocorticoid, regulates the inflammatory response (Newton and Holden, 2007), carbohydrate and lipid metabolism, and stress response (Kassel and Herrlich, 2007). Aldosterone regulates blood pressure by modulating fluid and electrolyte balance (Brizuela et ah, 2006 Foster, 2004). In the adrenal cortex, dehydroepiandrosterone (DHEA), dehy-droepiandrosterone sulfate (DHEA-S), and androstenedione are the androgens produced (Havelock et ah, 2004 Rainey et ah, 2002). 

The major androgen or androgen precursor produced by the adrenal cortex is dehydroepiandrosterone (DHEA). Most 17-hydroxypregnenolone follows the glucocorticoid pathway, but a small fraction is subjected to oxidative fission and removal of the two-carbon side chain through the action of 17,20-lyase. The lyase activity is actually part of the same enzyme (P450cl7) that catalyzes 17tt-hydroxylation. This is therefore a dual function protein. The lyase activity is important in both the adrenals and... 

The zona reticularis produces the androgens androstene-dione, dehydroepiandrosterone (DHEA), and the sulfated form of dehydroepiandrosterone (DHEA-S). Only small amounts of testosterone and estrogen are produced in the adrenal glands. Androstenedione and DHEA are converted in the periphery, largely to testosterone and estrogen. 

Androstenedione, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S) are other mildly androgenic compounds of secondary importance in males and females. The gonads and the adrenal cortex are capable of secreting androstenedione... 

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. 

Nature Dehydroepiandrosterone (DHEA), derived mainly from the adrenal cortex, is an androgen precursor and in peripheral tissues is converted by aromatase to estradiol, fit the plasma, DHEA is converted to DHEA sulfate (DHEAS). No specific physiologic function has been defined for DHEA or DHEAS. However, DHEA levels decrease during aging and possibly in some disease states, including advanced AIDS, diabetes, and systemic lupus erythematosus (in women). 

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