Time course of glyburide depletion by mouse hepatic S-9 fractions (A) and inhibition of glyburide depletion by KTZ (B). A, GLB depletion was performed by incubating GLB at 0.625 μM with S-9 fractions (1 mg/ml) of wild-type nonpregnant (solid squares, n = 7 per time point) or wild-type pregnant mice (solid triangles, n = 8 per time point) for up to 20 min. The amounts of GLB at time 0 were set as 100%. Shown are mean ± S.D. B, GLB depletion was performed as in A for 20 min in the absence (open bars) or presence (solid bars) of 1 μM KTZ. The amounts of GLB in the samples with no NADPH-regenerating system added were set as 100%. Shown are mean ± S.D. of six independent determinations. Significant differences: *, p < 0.05; ***, p < 0.005 by the Student's t test.