Effect of 3β-OH on anaesthetic endpoints. (a) Dose–response curve for loss of righting reflex (LORR) in WT and Cav3.1 KO mice with ED50 indicated on the top of the panel. (b) Left, percentage of animals that lost righting reflex under 80 mg kg−1 i.p. 3β-OH in WT (17 animals) and Cav3.1 KO (20 animals) cohorts (80 mg kg−1: χ2 = 9.79, P=0.002). (b) Right: duration of LORR under 80 mg kg−1 i.p. 3β-OH in WT (17 animals) and Cav3.1 KO (20 animals) mice (unpaired two-tailed t-test: t(35)=2.94, P=0.006). (c) 20 mg kg−1 3β-OH lowered the percent of isoflurane needed for LORR in WT and Cav3.1 KO mice (10 mice in each group, two-way RM analysis of variance [anova]: interaction F(1,18)=1.67, P=0.210; mutation effect F(1,18)=1.35, P=0.260; 3β-OH effect F(1,18)=42.19, P<0.001). (d) WT animals pretreated with 3β-OH needed significantly less time for induction with isoflurane compared with mutant animals (10 mice in each group, two-way RM anova: interaction F(1,18)=0.71, P=0.410; mutation effect F(1,18)=9.05, P=0.007; 3β-OH effect F(1,18)=1.59, P=0.223). ∗∗P<0.01, ∗∗∗P<0.001. 3β-OH, (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile; KO, knock-out; WT, wild-type; ED50, median effective dose; RM, definition.