The purpose of this study was to evaluate the effects on hormonal milieu of 1-year therapy with 10 mg/day oral dehydroepiandrosterone (DHEA) or 50 microg transdermal estradiol plus 100 mg/day oral micronized progesterone in a group of 20 healthy postmenopausal women (age=50-58 and years since menopause (ysm)=1-6) and also the effects observed by combining these two therapies in a group of 12 po...

A number of endogenous steroids exhibit rapid, nongenomic effects on the central nervous system and are called neuroactive steroids. The rapid mechanisms of action include modulation of gamma-aminobutyric acid type A (GABAA) and N-methyl-D-aspartate (NMDA) receptors, which are two receptors implicated in the behavioral effects of ethanol. It was hypothesized that neuroactive steroids that posit...

The effects of ganaxolone, a synthetic analog of the endogenous neuroactive steroid allopregnanolone, on the function and expression of GABA(A) receptors were determined. Electrophysiological recordings demonstrated that ganaxolone potentiated with a potency and efficacy similar to those of allopregnanolone the Cl- currents evoked by GABA at recombinant human GABA(A) receptors (comprising alpha...

Diverse γ-aminobutyric acid (GABAA) receptor modulators exhibited novel cytoprotective effects and mechanisms of action in rabbit renal proximal tubules subjected to mitochondrial inhibition (antimycin A) or hypoxia. Cytoprotective potencies (50% effective concentration, EC50) were 0.3 nM allopregnanolone (AP) > 0.4 nM 17α-OH-allopregnanolone (17α-OH-AP) > 30 nM dehydroepiandrosterone sulfate (...

Reduced pregnane neurosteroids such as allopregnanolone and pregnanolone are potent neuromodulators able to affect a number of membrane receptors, including gamma-aminobutyric acid (GABA)(A), N-methyl-D-aspartate (NMDA), 5-hydroxytryptamine (5-HT)(3), and sigma(1) receptors. The present study used a drug discrimination procedure to assess further the receptor effects of pregnanolone in vivo. Ra...

The female brain operates in a constantly changing chemical milieu caused by cyclical changes in gonadal hormones during the estrous cycle (menstrual cycle in women). Such hormones are highly lipophilic and pass readily from the plasma to the brain where they can influence neuronal function. It is becoming clear that the rapid reduction in peripheral circulating progesterone, which occurs durin...