title: Effects of insulin, glucagon, dexamethasone, cyclic GMP and spermine on the stability of phosphatidate phosphohydrolase activity in cultured rat hepatocytes.
abstract: Hepatocytes were preincubated with 10mM-glucagon and 100 microM-corticosterone to increase phosphatidate phosphohydrolase activity. Addition of 10 nM-glucagon or 100 microM-8-bromo cyclic GMP to a second incubation mixture that contained cycloheximide increased the half-life of the phosphohydrolase activity. Dexamethasone (100 nM) had no significant effect, but insulin (500 pM) or spermine (1 mM) decreased the half-life. None of these compounds altered the general rate of degradation of proteins labelled with [3H]leucine. There appears to be a specific control of the half-life of phosphatidate phosphohydrolase activity, which could contribute to its long-term regulation in the liver.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003345:Corticosterone / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology; D006207:Half-Life; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D010711:Phosphatidate Phosphatase / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D013096:Spermine / Q000494:pharmacology
chemical_list: D007328:Insulin; D011506:Proteins; D013096:Spermine; D003907:Dexamethasone; D005934:Glucagon; D010744:Phosphoric Monoester Hydrolases; D010711:Phosphatidate Phosphatase; D006152:Cyclic GMP; D003345:Corticosterone