title: The effect of serotonin inhibition on initial microvessel hemostasis and platelet aggregation in vivo.
abstract: The role of serotonin (5-HT) in initial microvascular hemostasis is not fully understood. This study was made to evaluate the effect on hemostatic plug formation and laser-induced arteriolar microembolism of different substances which counteract the effect of 5-HT. Hemostatic plug formation time and stability was measured in the rabbit mesenteric microcirculation and laser-induced embolism in the rabbit ear chamber. Ketanserine, a selective 5-HT2-receptor blocker shortened arteriolar hemostatic plug formation time. Dihydroergotamine, an unselective blocker (with 5-HT-and alpha-adrenergic receptor affinity) increased venular hemostatic plug formation time and also decreased the hemostatic plug stability. Laser-induced platelet embolism was unaltered after both ketanserine and dihydroergotamine administration. The magnitude of these changes seems to exclude an important effect of 5-HT in initial microvessel hemostasis or on platelet activity.
mesh_terms: D000818:Animals; D001760:Bleeding Time; D004087:Dihydroergotamine / Q000494:pharmacology; D005260:Female; D006487:Hemostasis / Q000187:drug effects*; D007650:Ketanserin; D008297:Male; D008638:Mesenteric Arteries / Q000503:physiopathology; D008642:Mesenteric Veins / Q000503:physiopathology; D008833:Microcirculation / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D011817:Rabbits; D012702:Serotonin Antagonists / Q000494:pharmacology*
chemical_list: D010880:Piperidines; D012702:Serotonin Antagonists; D004087:Dihydroergotamine; D007650:Ketanserin