a steroid secreted chiefly by the adrenal cortex, but also by the testis; it is the principal precursor of urinary 17-ketosteroids. Weakly androgenic itself, it is metabolized to delta-5 androstenediol, a hormone with both androgenic and estrogenic effects, and is one of the precursors of testosterone. Serum levels are elevated in adrenal virilism. It may function as a neurotransmitter. SYN: androstenolone, dehydroisoandrosterone.DHEA secretion begins during fetal life, reaches a peak in the 3rd decade, and declines steadily thereafter; the level at age 80 is only 10–20% of the peak level. This decline has been speculatively associated with the changes of aging. Commercial formulations of DHEA are marketed as dietary supplements, although this substance is neither a nutrient nor a component of the human food chain. Available from health food stores in 10-, 25-, and 50-mg capsules, DHEA has been promoted for the prevention of degenerative diseases including atherosclerosis, Alzheimer dementia, and parkinsonism, and other effects of aging. None of the alleged benefits have been demonstrated in large, randomized clinical trials. Long-term administration to postmenopausal women has been associated with insulin resistance, hypertension, and reduction of LDL cholesterol. An analysis of 16 preparations of DHEA by high-performance liquid chromatography showed a variation in content from 0–150% of the labeled strength; only 7 products fell between the expected 90–110% of labeled strength.

Medical dictionary. 2011.

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  • androstenolone — SYN: dehydro 3 epiandrosterone …   Medical dictionary

  • dehydroisoandrosterone — SYN: dehydro 3 epiandrosterone. * * * de·hy·dro·iso·an·dros·ter·one (.)dē .hī drō .ī sō an dräs tə .rōn n DEHYDROEPIANDROSTERONE * * * de·hy·dro·iso·an·dros·ter·one (de hi″dro i″so an drosґtər ōn) dehydroepiandrosterone …   Medical dictionary

  • DHEA — Abbreviation for dehydro 3 epiandrosterone. Abbreviation for dehydroepiandrosterone. * * * dehydroepiandrosterone * * * DHEA abbr dehydroepiandrosterone * * * see dehydroepiandrosterone * * * dehydroepiandrosterone …   Medical dictionary

  • HORMONES — Chez les animaux pluricellulaires, la coordination des fonctions exercées par les différents organes repose sur des systèmes de communication qui opèrent au sein de l’organisme pour maintenir l’équilibre fonctionnel indispensable à la vie [cf.… …   Encyclopédie Universelle

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