Fig. 7.

Appropriate blunting of insulin signaling with PI3K inhibitor prevents the development of insulin resistance caused by prolonged exposure to either fat or insulin in hepatocytes. Hep1c1c7 cells were treated with the PI3K inhibitor LY-294002 (10 μM) for 24 h, followed by treatment with insulin (10 nm) or oleate (0.5 mM) for additional 24 h. A: the cells were washed extensively with warm PBS for 30 min and then treated with 1 nM insulin for 5 min. Phosphorylated and total Akt were determined by immunoblotting and quantified. Triglyceride content (B) and GSH/GSSG ratio (C) were evaluated. Results represent means ± SE from 3 independent experiments, each in triplicate. Veh: saline. *P < 0.05, **P < 0.01, and ***P < 0.001 vs. vehicle.