p110γ inhibition impairs GIP-R, but not GLP-1-R-stimulated insulin secretion from mouse islets.
A, expression of p110γ was confirmed by Western blot of protein lysates from INS-1 832/13 (I), mouse islets (M), and human islets (H). B, p110γ, p110α, and p110β protein expression levels from INS-1 832/13 cells following overnight treatment with either DMSO or AS604850 (1 μmol/liter). β-Actin was used as a loading control. C, glucose and GIP (100 nmol/liter; 1 h) stimulated insulin secretion was measured from mouse islets treated overnight with either DMSO (open bars) or AS604850 (1 μmol/liter; black bars). D, glucose and GLP-1-stimulated (10 nmol/liter; 1 h) or Ex-4-stimulated (100 nmol/liter; 1 h) insulin secretion was measured from mouse islets treated overnight with either DMSO (open bars) or AS604850 (1 μmol/liter; black bars). Inset shows total insulin content. *, p < 0.5; **, p < 0.01; ns, not significant.