In vivo regulation of protein-serine kinases by insulin in skeletal muscle of fructose-hypertensive rats

The effects of tail-vein insulin injection on the regulation of protein-serine kinases in hindlimb skeletal muscle were studied in hyperinsulinemic hypertensive fructose-fed (FF) rats that had been fasted overnight. Basal protein kinase B (PKB) activity increased about twofold in FF rats and was not further stimulated by insulin. Findings showed that the phosphatidylinositol 3-kinase (PI3K) -> PKB -> S6 kinase (S6K) pathway was upregulated under basal conditions. Also, insulin stimulation of PI3K and S6K activities was enhanced.