Simultaneous quantification of GABAergic 3α,5α/3α,5β neuroactive steroids in human and rat serum

Porcu, Patrizia; O'Buckley, Todd K.; Alward, Sarah E.; Marx, Christine E.; Shampine, Lawrence J.; Girdler, Susan S.; Morrow, A. Leslie

doi:10.1016/j.steroids.2008.12.015

Cited by 62 publications

(69 citation statements)

References 71 publications

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“…Higher bioavailability of 5b-AP could contribute to the anticonvulsant effect in vivo despite less overall potentiation of GABAergic current in the slice (Fig. 6A) (Porcu et al, 2009). At elevated concentrations that activate both synaptic and extrasynaptic receptor types, it is feasible that the direct binding of 5b-AP to receptors overcomes the reduced effects on tonic current (Hosie et al, 2006).…”

Section: Neurosteroid Sars At Extrasynaptic Gaba a Receptorsmentioning

confidence: 99%

Neurosteroid Structure-Activity Relationships for Functional Activation of Extrasynaptic GABAA Receptors

Carver

Reddy

2016

Journal of Pharmacology and Experimental Therapeutics

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Synaptic GABA A receptors are primary mediators of rapid inhibition in the brain and play a key role in the pathophysiology of epilepsy and other neurologic disorders. The d-subunit GABA A receptors are expressed extrasynaptically in the dentate gyrus and contribute to tonic inhibition, promoting network shunting as well as reducing seizure susceptibility. However, the neurosteroid structure-function relationship at dGABA A receptors within the native hippocampus neurons remains unclear. Here we report a structure-activity relationship for neurosteroid modulation of extrasynaptic GABA A receptor-mediated tonic inhibition in the murine dentate gyrus granule cells. We recorded neurosteroid allosteric potentiation of GABA as well as direct activation of tonic currents using a wide array of natural and synthetic neurosteroids. Our results shows that, for all neurosteroids, the C3a-OH group remains obligatory for extrasynaptic receptor functional activity, as C3b-OH epimers were inactive in activating tonic currents. Allopregnanolone and related pregnane analogs exhibited the highest potency and maximal efficacy in promoting tonic currents. Alterations at the C17 or C20 region of the neurosteroid molecule drastically altered the transduction kinetics of tonic current activation. The androstane analogs had the weakest modulatory response among the analogs tested. Neurosteroid potentiation of tonic currents was completely (approximately 95%) diminished in granule cells from d-knockout mice, suggesting that d-subunit receptors are essential for neurosteroid activity. The neurosteroid sensitivity of dGABA A receptors was confirmed at the systems level using a 6-Hz seizure test. A consensus neurosteroid pharmacophore model at extrasynaptic dGABA A receptors is proposed based on a structure-activity relationship for activation of tonic current and seizure protection.

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Section: Neurosteroid Sars At Extrasynaptic Gaba a Receptorsmentioning

confidence: 99%

Neurosteroid Structure-Activity Relationships for Functional Activation of Extrasynaptic GABAA Receptors

Carver

Reddy

2016

Journal of Pharmacology and Experimental Therapeutics

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“…Plasma levels of neurosteroids (ie, pregnenolone, allopregnanolone, pregnanolone (ie, 3α-hydroxy-5β-pregnan-20-one), 3α,5α-androsterone, and 3α,5β-androsterone) were analyzed by gas chromatography with mass spectrometry (GC-MS) at the University of North Carolina at Chapel Hill as described previously (Porcu et al, 2009). Plasma progesterone levels were assayed at the NIH Clinical Center Department of Laboratory Medicine by LC-MS/MS, and luteal plasma levels o2 ng/ml were considered to be consistent with either anovulation or a clinic visit too late or early in the luteal phase and, therefore, were not included in comparisons of plasma neurosteroid levels (see below).…”

Section: Hormone Assaysmentioning

confidence: 99%

5α-Reductase Inhibition Prevents the Luteal Phase Increase in Plasma Allopregnanolone Levels and Mitigates Symptoms in Women with Premenstrual Dysphoric Disorder

Martinez¹,

Rubinow

Nieman

et al. 2015

Neuropsychopharmacol

118

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Changes in neurosteroid levels during the luteal phase of the menstrual cycle may precipitate affective symptoms. To test this hypothesis, we stabilized neurosteroid levels by administering the 5α-reductase inhibitor dutasteride to block conversion of progesterone to its neurosteroid metabolite allopregnanolone in women with premenstrual dysphoric disorder (PMDD) and in asymptomatic control women. Sixteen women with prospectively confirmed PMDD and 16 control women participated in one of two separate randomized, doubleblind, placebo-controlled, cross-over trials, each lasting three menstrual cycles. After one menstrual cycle of single-blind placebo, participants were randomized to receive, for the next two menstrual cycles, either double-blind placebo or dutasteride (low-dose 0.5 mg/ day in the first eight PMDD and eight control women or high-dose 2.5 mg/day in the second group of women). All women completed the daily rating form (DRF) and were evaluated in clinic during the follicular and luteal phases of each menstrual cycle. Main outcome measures were the DRF symptoms of irritability, sadness, and anxiety. Analyses were performed with SAS PROC MIXED. In the low-dose group, no significant effect of dutasteride on PMDD symptoms was observed compared with placebo (ie, symptom cyclicity maintained), and plasma allopregnanolone levels increased in women with PMDD from follicular to the luteal phases, suggesting the absence of effect of the lowdose dutasteride on 5α-reductase. In contrast, the high-dose group experienced a statistically significant reduction in several core PMDD symptoms (ie, irritability, sadness, anxiety, food cravings, and bloating) on dutasteride compared with placebo. Dutasteride had no effect on mood in controls. Stabilization of allopregnanolone levels from the follicular to the luteal phase of the menstrual cycle by blocking the conversion of progesterone to its 5α-reduced neurosteroid metabolite mitigates symptoms in PMDD. These data provide preliminary support for the pathophysiologic relevance of neurosteroids in this condition.

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“…Ethanol activates the hypothalamic-pituitary-adrenal (HPA) axis (Rivier et al, 1984;VanDoren et al, 2000), increasing 3a,5a-THP and 3a,5a-THDOC in the blood plasma, cerebral cortex, and hippocampus (Barbaccia et al, 1999;Porcu et al, 2009;VanDoren et al, 2000). However, it is not known whether this elevation of GABAergic steroids originates only from the periphery or whether there are changes in levels of GABAergic steroids that occur locally in the brain.…”

Section: Introductionmentioning

confidence: 99%

Ethanol Alters Local Cellular Levels of (3α,5α)-3-Hydroxypregnan-20-one (3α,5α-THP) Independent of the Adrenals in Subcortical Brain Regions

Cook

Nelli

Neighbors

et al. 2014

Neuropsychopharmacol

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The neuroactive steroid (3a,5a)-3-hydroxypregnan-20-one (3a,5a-THP or allopregnanolone) is a positive modulator of GABA A receptors synthesized in the brain, adrenal glands, and gonads. In rats, ethanol activates the hypothalamic-pituitary-adrenal axis and elevates 3a,5a-THP in plasma, cerebral cortex, and hippocampus. In vivo, these effects are dependent on both the pituitary and adrenal glands. In vitro, however, ethanol locally increases 3a,5a-THP in hippocampal slices, in the absence of adrenal influence. Therefore, it is not known whether ethanol can change local brain levels of 3a,5a-THP in vivo, independent of the adrenals. To directly address this controversy, we administered ethanol (2 g/kg) or saline to rats that underwent adrenalectomy (ADX) or received sham surgery and performed immunohistochemistry for 3a,5a-THP. In the medial prefrontal cortex (mPFC), ethanol increased 3a,5a-THP after sham surgery, compared with saline controls, with no ethanol-induced change in 3a,5a-THP following ADX. In subcortical regions, 3a,5a-THP was increased independent of adrenals in the CA1 pyramidal cell layer, dentate gyrus polymorphic layer, bed nucleus of the stria terminalis, and paraventricular nucleus of the hypothalamus. Furthermore, ethanol decreased 3a,5a-THP labeling in the nucleus accumbens shore and central nucleus of the amygdala, independent of the adrenal glands. These data indicate that ethanol dynamically regulates local 3a,5a-THP levels in several subcortical regions; however, the adrenal glands contribute to 3a,5a-THP elevations in the mPFC. Using double immunofluorescent labeling we determined that adrenal dependence of 3a,5a-THP induction by ethanol is not due to a lack of colocalization of 3a,5a-THP with the cholesterol transporters steroidogenic acute regulatory protein (StAR) or translocator protein (TSPO).

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Simultaneous quantification of GABAergic 3α,5α/3α,5β neuroactive steroids in human and rat serum

Cited by 62 publications

References 71 publications

Neurosteroid Structure-Activity Relationships for Functional Activation of Extrasynaptic GABAA Receptors

Neurosteroid Structure-Activity Relationships for Functional Activation of Extrasynaptic GABAA Receptors

5α-Reductase Inhibition Prevents the Luteal Phase Increase in Plasma Allopregnanolone Levels and Mitigates Symptoms in Women with Premenstrual Dysphoric Disorder

Ethanol Alters Local Cellular Levels of (3α,5α)-3-Hydroxypregnan-20-one (3α,5α-THP) Independent of the Adrenals in Subcortical Brain Regions

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