FIG. 2.

First-phase GSIR and l-arginine potentiation are increased in absence of PI4P5Kα. A: WT and KO mice received a bolus of 20% glucose to increase serum glucose levels >250 mg/dL and were then maintained at that level by intravenous infusion adjusted for the change in serum glucose levels over time. B: Insulin secretion during the hyperglycemic clamp. Blood samples were taken at the intervals shown and assayed for serum insulin levels. At min 80, a bolus of 20% l-arginine and then an l-arginine infusion were added. Each experiment group was composed of four age-matched male mice. *Significant P values as indicated. Statistical significance determined by Student t test.