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.
Tsuji
T
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Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
Cook
D A
DA
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