title: The 5-hydroxytryptamine receptor of blood platelets.
abstract: Blood platelets show specific, high affinity binding of 3H-5-hydroxytryptamine, 3H-ketanserin and 3H-D-lysergic acid diethylamide. 5-HT-antagonists are considerably more potent than agonists regarding both the displacement of specifically bound 3H-ketanserin and the shape change reaction mediated by the 5-HT-receptor. The latter depends on a rise of free intracellular Ca2+. The binding site for 3H-ketanserin and the site at which the 5-HT-induced shape change is triggered show the characteristics of a 5-HT2-receptor whose intracellular mediator seems to be Ca2+. The 5-HT2-receptor of platelets may be used as a partial model for that in neurons; however, it remains to be elucidated whether Ca2% is a mediator of the latter.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001792:Blood Platelets / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D007650:Ketanserin; D007700:Kinetics; D008238:Lysergic Acid Diethylamide / Q000097:blood; D008959:Models, Neurological; D009474:Neurons / Q000378:metabolism*; D010880:Piperidines / Q000097:blood; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000097:blood*; D012702:Serotonin Antagonists / Q000097:blood / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D010880:Piperidines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D008238:Lysergic Acid Diethylamide; D007650:Ketanserin; D002118:Calcium