Activation of phospholipid methyltransferase by glucagon in rat hepatocytes.
Glucagon produces a time- and dose-dependent activation of phospholipid methyltransferase activity in isolated rat hepatocytes. Half-maximal effect is caused by a dose of glucagon of 1 x 10(-10) M. This activation is due to an increase of the Vmax value of the enzyme, without affecting the Km value for S-adenosylmethionine. Exogenous cyclic AMP added to isolated rat hepatocytes mimics the effect of glucagon, and the activation of phospholipid methyltransferase by a nonsaturating concentration of glucagon is spontaneously reversible within 40 min of incubation.
D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D004789:Enzyme Activation; D005934:Glucagon / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008780:Methyltransferases / Q000378:metabolism*; D050941:Phosphatidyl-N-Methylethanolamine N-Methyltransferase; D050918:Phosphatidylethanolamine N-Methyltransferase; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology
D012969:Sodium Fluoride; D005934:Glucagon; D000242:Cyclic AMP; D008780:Methyltransferases; D050918:Phosphatidylethanolamine N-Methyltransferase; D050941:Phosphatidyl-N-Methylethanolamine N-Methyltransferase