Effect of ketanserin on 5-hydroxytryptamine-induced constriction in isolated, perfused canine basilar arteries exposed to blood.
The blocking effect of ketanserin, a 5-hydroxytryptamine (5-HT)2 receptor antagonist, was examined on responses to intra-luminal 5-HT or potassium chloride (KCl) in isolated and perfused canine basilar arteries before and after extraluminal whole blood by means of the stainless-steel cannula inserting method. Four hours after the application of blood, the constriction to 5-HT was significantly enhanced, while that to KCl was significantly attenuated. The absolute value in the decrease of perfusion pressure for the 5-HT-induced constriction sensitive to ketanserin was much greater after the blood application than that before the application. It is suggested that the augmentation of cerebrovascular responses to 5-HT in the early stage immediately after subarachnoid haemorrhage (SAH) might be mediated by 5-HT2 receptors at least in part. This early constrictor mechanism may be implicated in the aetiology of the following late stage of cerebral vasospasm after SAH.
Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
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Tsuji
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Cook
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects*; D004285:Dogs; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D007650:Ketanserin / Q000494:pharmacology*; D010477:Perfusion; D011189:Potassium Chloride / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology*; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D011189:Potassium Chloride; D007650:Ketanserin