title: Agonist-specific desensitization of shape change of platelets.
abstract: Using scanning electron microscopy and light scattering we have investigated the shape change of bovine platelets. The extents of shape change obtained by ADP and 5-hydroxytryptamine(5HT) increased in dose-dependent manner, and the maximum obtained by these agonists were additive. The agonist-specific desensitization in shape change was observed with ADP, 5HT and thrombin. The extent of desensitization by pre-exposure to ADP was dependent upon the concentration of ADP. It was strongly indicated that receptors or their subsequent stimuli-transmission apparatus became unable to respond to further stimulation after the exposure to the initial stimulation.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000648:ultrastructure*; D002417:Cattle; D003888:Desensitization, Immunologic; D004307:Dose-Response Relationship, Radiation; D008854:Microscopy, Electron; D010974:Platelet Aggregation; D012542:Scattering, Radiation; D012701:Serotonin / Q000494:pharmacology
chemical_list: D012701:Serotonin; D000244:Adenosine Diphosphate