title: Prostaglandin E1 and forskolin antagonize C-kinase activation in the human platelet.
abstract: In human platelets, prostaglandin E1 and forskolin inhibit 5-hydroxytryptamine-induced phospholipase C, C-kinase and myosin light-chain kinase activity in a concentration-dependent way. Phospholipase C activation, however, was only partly inhibited, and this at higher concentrations than the protein kinases. Direct activation of the C kinase either by exogenous synthetic diacylglycerol or by 12-O-tetradecanoylphorbol 13-acetate was antagonized by prostaglandin E1 and forskolin. Since C-kinase activation is one of the key events in excitatory signal transduction in the platelets, we suggest that the inhibitory effect of agents that increase platelet cyclic AMP on platelet secretion and aggregation might reside in their capacity to antagonize C-kinase activity.
authors.affiliation: Department of Biochemistry, Janssen Pharmaceutica, Beerse, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: de Chaffoy de Courcelles
authors.forename: P
authors.initials: P
authors.lastname: Roevens
authors.forename: H
authors.initials: H
authors.lastname: Van Belle
mesh_terms: D000527:Alprostadil / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D002118:Calcium / Q000097:blood; D005576:Colforsin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000097:blood; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000097:blood; D012701:Serotonin / Q000494:pharmacology
chemical_list: D004075:Diglycerides; D005576:Colforsin; D012701:Serotonin; C038237:1-oleoyl-2-acetylglycerol; D000242:Cyclic AMP; D011493:Protein Kinase C; D000527:Alprostadil; D002118:Calcium