Control of glycogen phosphorylase interconversion by phorbol esters, diacylglycerols, Ca2+ and hormones in isolated rat hepatocytes.

摘要: In isolated rat hepatocytes: phosphorylase activation by the ionophore A23187 was enhanced in presence of tumour-promoting phorbol esters and 1,2- (but not 1,3-) diacylglycerols (dioleoyl- oleoylacetyl-glycerol), with a similar dose-dependency; phenylephrine (1 microM) vasopressin or glucagon) inhibited both diacylglycerols, but different dose-dependency: complete inhibition achieved concentrations two orders magnitude lower than those diacylglycerol; binding alpha 1-adrenergic antagonist [3H]prazosin its displacement unlabelled prazosin significantly affected esters. The possible involvement protein kinase C control interconversion is discussed.