Androstenedione
Androstenedione is a weak androgen made in the adrenals and gonads, an intermediate on the pathway from DHEA to testosterone and estrone. It converts to testosterone via 17-beta-hydroxysteroid dehydrogenase and to estrone via aromatase; after menopause, when ovarian follicles are depleted, androstenedione becomes the main hormone secreted by the residual ovary, and peripheral aromatization of it is a major source of postmenopausal estrogen. It was sold over the counter in the US as a bodybuilding/anti-aging supplement (marketed to raise testosterone) until the FDA declared it an adulterated dietary ingredient in March 2004, and Congress reclassified it as a controlled anabolic steroid later that year.[1]
Peat's view
[edit]The placenta converts 16-hydroxy androstenedione and 16-hydroxy-DHEA into estriol; Peat linked their decline to fetal exhaustion or a dying fetal-placental system.[2]
Function/Mechanism of Action
[edit]Because androstenedione is a direct aromatase substrate, its physiological effects in older or menopausal females run partly through the estrogen it is converted into rather than through direct androgen action. In middle-aged, ovariectomized (surgically menopausal) rats, higher circulating androstenedione correlated with more working- and reference-memory errors on maze tasks, and the highest dose tested impaired performance directly, a pattern consistent with Peat's general view of unopposed estrogen as harmful to brain function.[3] A related line of research found that blocking aromatase (preventing conversion of androgens like androstenedione into estrogen) reversed memory impairment in ovariectomized rats, and that the mainstream claim of estrogen as protective against Alzheimer's-type memory decline lacks supporting evidence.[4]
See also
[edit]References
[edit]- ↑ "FDA Warns Manufacturers To Stop Distributing Products Containing 'Andro'", ScienceDaily, March 2004.
- ↑ Ray Peat, "Estriol, DES, DDT, Etc.: A Review of the Use of Estrogens." "The conversion of 16-hydroxy androstenedione and 16-hydroxy-DHEA into estriol by the placenta would also cause fetal exhaustion or death to result in lower estriol production."
- ↑ Camp BW, Gerson JE, Tsang CW, Villa SR, Acosta JI, Braden BB, Hoffman AN, Conrad CD, Bimonte-Nelson HA. "High serum androstenedione levels correlate with impaired memory in the surgically menopausal rat: a replication and new findings," Eur J Neurosci. 2012;36(8):3086-3095. PMID 22758646.
- ↑ "Lowering estrogen prevents memory decline in menopausal females", Georgi Dinkov (Haidut), haidut.me.