Inhibitory action of guanosine 3',5'-monophosphate on thrombin-induced calcium mobilization in human platelets.
During thrombin-induced serotonin release from platelets, phosphorylation of myosin light chain was increased. This protein phosphorylation, which is initiated by Ca2+ mobilization, and serotonin release were inhibited progressively by increasing concentrations of sodium nitroprusside, a potent stimulator of platelet guanylate cyclase, or 8-bromo-cyclic GMP. Thrombin-induced increase in cytoplasmic free Ca2+, which was also inhibited by these drugs in a dose-dependent manner. These results provide evidence that an increase in platelet cyclic GMP inhibits thrombin-induced Ca2+ mobilization and prevents platelet activation.
D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D006801:Humans; D009599:Nitroprusside / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D013268:Stimulation, Chemical; D013917:Thrombin / Q000494:pharmacology*
D009599:Nitroprusside; C016276:8-bromocyclic GMP; D012701:Serotonin; D013917:Thrombin; D006152:Cyclic GMP; D002118:Calcium