A method for investigating the role of calcium in the shape change, aggregation and serotonin release of rat platelets.
1. Effects of the platelet secretagogues thrombin and Concanavalin A (Con A) on shape change and release have been studied under conditions where external Ca2+ and ADP have been controlled. 2. In the absence of detectable aggregation both Con A- and thrombin-induced release of serotonin are markedly dependent upon extracellular calcium. 3. Con A, unlike thrombin, does not produce aggregation in calcium-supplemented medium. 4. The above property of Con A suggests that, in combination with added creatine phosphate and creatine phosphokinase, this ligand will be of value in the analysis of calcium-dependent release in platelets.
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D003208:Concanavalin A / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D012701:Serotonin / Q000097:blood / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology
D003208:Concanavalin A; D012701:Serotonin; D013917:Thrombin; D002118:Calcium