Stimulation of pyruvate kinase phosphatase activity by insulin in isolated rat hepatocytes.
Addition of insulin (10(-8)M) to hepatocytes, incubated either in the absence or in the presence of a suboptimal concentration of glucagon, caused the reactivation of pyruvate kinase and simultaneously provoked a transient stimulation of pyruvate kinase phosphatase activity (40-70% over control values). The stimulatory effect of insulin on pyruvate kinase phosphatase activity was dose-dependent (ED50 = 1 to 2 X 10(-11)M) and persisted after Sephadex G-25 filtration or ammonium sulfate precipitation of hepatocytes extracts. Our results demonstrate that insulin exerts a short-term regulation on hepatic pyruvate kinase phosphatase activity.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005934:Glucagon / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D007328:Insulin; D005934:Glucagon; D011770:Pyruvate Kinase; C032653:pyruvate kinase phosphatase; D010749:Phosphoprotein Phosphatases; D008274:Magnesium