Is dehydroepiandrosterone a hormone?

Abstract

Dehydroepiandrosterone (DHEA) is not a hormone but it is a very important prohormone secreted in large amounts by the adrenals in humans and other primates, but not in lower species. It is secreted in larger quantities than cortisol and is present in the blood at concentrations only second to cholesterol. All the enzymes required to transform DHEA into androgens and/or estrogens are expressed in a cellspecific manner in a large series of peripheral target tissues, thus permitting all androgen-sensitive and estrogensensitive tissues to make locally and control the intracellular levels of sex steroids according to local needs. This new field of endocrinology has been called intracrinology. In women, after menopause, all estrogens and almost all androgens are made locally in peripheral tissues from DHEA which indirectly exerts effects, among others, on bone formation, adiposity, muscle, insulin and glucose metabolism, skin, libido and well-being. In men, where the secretion of androgens by the testicles continues for life, the contribution of DHEA to androgens has been best evaluated in the prostate where about 50% of androgens are made locally from DHEA. Such knowledge has led to the development of combined androgen blockade (CAB), a treatment which adds a pure anti-androgen to medical (GnRH agonist) or surgical castration in order to block the access of the androgens made locally to the androgen receptor. In fact, CAB has been the first treatment demonstrated to prolong life in advanced prostate cancer while recent data indicate that it can permit long-term control and probably cure in at least 90% of cases of localized prostate cancer. The new field of intracrinology or local formation of sex steroids from DHEA in target tissues has permitted major advances in the treatment of the two most frequent cancers, namely breast and prostate cancer, while its potential use as a physiological HRT could well provide a physiological balance of androgens and estrogens, thus offering exciting possibilities for women's health at menopause.

Domestication effects on behavioural and hormonal responses to acute stress in chickens

“…We could speculate that the higher basal levels of DHEA in WL might be related to the greater social tolerance shown by WL females [53]. To our knowledge this is the first study which clearly shows that short term stress causes a decrease of blood DHEA levels in any avian breed, and in most species the circulating levels are very low [54].…”

Can endocrine disruptors influence neuroplasticity in the aging brain?

“…The underlying mechanisms are presently uncertain; MacLusky et al (2006) point to a varety of possibilities that might be exploited clinically. DHEA, considered a "weak" androgen, also increases spine synaptic density (Parducz et al, 2006) but as shown by Labrie (2005) and others, can be aromatized to estradiol.…”

“…The adrenal secretes dihydroepiandosterone (DHEA) which acts on peripheral tissues such as the mammary gland and prostrate. DHEA begins to fall steeply during middle age (Labrie et al 2001(Labrie et al ,2005. Such changes evoke questions about how measures of reduced androgen function such as diminished circulating free testosterone, might promote Alzheimer's disease (Hogervorst et al, 2004;Moffat et al, 2004).…”

Affectionate Communication Received from Spouses Predicts Stress Hormone Levels in Healthy Adults

“…Dehydroepiandrosterone-sulfate (DHEA-S), a derivative of dehydroepiandrosterone, is also an adrenal steroid. Unlike cortisol, DHEA-S is not a hormone itself, but rather an important prohormone, meaning that it is a substance that converts to other hormones (Labrie et al, 2005). Specifically, DHEA-S is a precursor to androstenedione, testosterone, and estrogens in adolescents and adults (Labrie, Luu-The, Labrie, & Simard, 2001).…”