Microsomal CA2+ uptake in human platelets is stimulated by calmodulin.
Calcium accumulating vesicles were prepared from washed human platelets. Ca2+ uptake could be stimulated with calmodulin. The stimulation of Ca2+ uptake was not abolished by the adenylate cyclase inhibitor 2',5'-dideoxyadenosine, thus excluding enhanced cAMP formation as a possible cause for the calmodulin effect. Our findings suggest that, in addition to cAMP, calmodulin is also involved in the regulation of platelet free Ca2+ concentrations, i.e. Ca2+ homeostasis in platelets is under dual control.
D000262:Adenylyl Cyclases / Q000097:blood; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000378:metabolism*; D001921:Brain; D002118:Calcium / Q000097:blood*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002417:Cattle; D000242:Cyclic AMP / Q000494:pharmacology; D003839:Deoxyadenosines / Q000031:analogs & derivatives / Q000494:pharmacology; D016048:Dideoxyadenosine / Q000031:analogs & derivatives*; D006706:Homeostasis; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism*; D010070:Oxalates / Q000494:pharmacology
D002147:Calmodulin; D003839:Deoxyadenosines; D007093:Imidazoles; D010070:Oxalates; D016048:Dideoxyadenosine; C031938:calmidazolium; C021008:2',5'-dideoxyadenosine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D002118:Calcium