TABLE 2.
EC50 and maximum ΔF/F0 values (95% confidence interval in the parenthesis) for NAS and related compounds and benzodiazepines to increase FMP-Red-Dye flourescence in cells expressing α1β3γ2 and α4β3δ GABAAR in the absence of GABA
Dose-response curves were fit by nonlinear regression with a four-parameter logistic equation. Statistical differences among EC50 and maximum ΔF/F0 values were assessed independently by one-way analysis of variance with post hoc pairwise comparisons using Tukey’s honest significant difference test. On α1β3γ2 GABAARs, eltanolone with an IC50 value of 8 nM and maximum of 0.17 is the most potent and efficacious compound. Although on α4β3δ GABAARs, eltanolone with an IC50 value of 6 nM is the most potent compound, and XJ-42 with a maximum of 0.41 is the most efficacious compound. Each data point represents the mean (with 95% confidence interval in parenthesis) of measurements in 10 wells. *P < 0.001 when comparing IC50 values or maximum of compounds within each receptor isoform.
| Compound Common Name (Systematic Name) |
α1β3γ2 (95% CI) |
α4β3δ (95% CI ) |
||
|---|---|---|---|---|
| EC50 | Maximum ΔF/F0 | EC50 | Maximum ΔF/F0 | |
| Allopregnanolone (3α-hydroxy-5α-pregnan-20-one) | 9 nM * (7–11 nM) | 0.13 (0.12–0.13) | 27 nM (18–42 nM) | 0.16 (0.15–0.17) |
| Ganaxolone (3α-hydroxy-3β-methyl-5α-pregnan-20-one) | 24 nM (18–32 nM) | 0.14 (0.13–0.14) | 40 nM (21–73 nM) | 0.17 (0.15–0.18) |
| Eltanolone (3α-hydroxy-5β-pregnan-20-one) | 8 nM * (5–14 nM) | 0.17 * (0.16–0.18) | 6 nM * (2.4–16 nM) | 0.14 (0.12–0.15) |
| XJ-42 (3α,5α,20E)-3-hydroxy-13,24-cyclo-18-norcholan-20-ene-21-carbonitrile) | 11 nM * (7–17 nM) | 0.13 (0.12–0.14) | 74 nM (47–116 nM) | 0.41 * (0.38–0.45) |
| 5β,3α-THDOC (5β-pregnan-3α,21-diol-20-one) | 16 nM (6–45 nM) | 0.09 (0.08–0.10) | 54 nM (12–230 nM) | 0.09 (0.06–0.12) |
| Alphadolone 21-acetate (5α-pregnan-3α,21-diol-11, 20-dione 21-acetate) | 60 nM (33–100 nM) | 0.08 (0.07–0.09) | 700 nM (381–1220 nM) | 0.14 (0.1–0.18) |
| Alphaxalone ((3α,5α)-3-hydroxypregnane-11,20-dione) | 26 nM (13–54 nM) | 0.11 (0.10–0.11) | 83 nM (72–97 nM) | 0.13 (0.11–0.15) |
| Androsterone (5α-androstan-3α-ol-17-one) | 300 nM (200–551 nM) | 0.16 * (0.14–0.18) | >1 µM | |
| Etiocholanolone (5β-androstan-3α-ol-17-one) | >1 µM | >5 µM | ||
| Org 20599 ((2β,3α,5α)-21-chloro-3-hydroxy-2-(4-morpholinyl)pregnan-20-one) | >1 µM | >1 µM | ||
| UCI-50027 (3-[3α-hydroxy-3β-methyl-5α-androstan-17β-yl]-5(hydroxymethyl)isoxazole) | >5 µM | >5 µM | ||
| Progesterone (pregn-4-ene-3,20-dione) | >5 µM | >5 µM | ||
| Epiandrosterone (5α-androstan-3β-ol-17-one) | >5 µM | >5 µM | ||
| Indiplon (N-methyl-N-[3-[3-(2-thienylcarbonyl)pyrazolo[1,5-α]pyrimidin-7-yl]phenyl]-acetamide) | >5 µM | >5 µM | ||
| Androstenediol (5-Androsten-3β, 17β-diol) | >5 µM | >5 µM | ||
| Dehydroepiandrosterone (DHEA) acetate | >5 µM | >10 µM | ||
| Dehydroepiandrosterone (DHEA) | >5 µM | Inactive | ||
| 20α-Dihydropregnenolone (5-pregnen-3β,20α-diol) | >10 µM | >10 µM | ||
| Ursodeoxycholic acid (sodium salt) (3,7-dihydroxy-cholan-24-oic acid, monosodium salt) | Inactive | Inactive | ||
| Cortisol (4-pregnen-11β,17,21-triol-3,20-dione) | Inactive | Inactive | ||
| Diazepam (7-chloro-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one) | >10 µM | >10 µM | ||
| Midazolam (8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine) | >10 µM | >10 µM | ||
| Zolpidem (N,N,6-trimethyl-2-(4-methylphenyl)-imidazo[1,2-a]pyridine-3-acetamide) | >10 µM | >10 µM | ||
CI, confidence interval.