5-Hydroxytryptamine receptors. Contractile activity and mode of inhibition by methysergide in mammalian intracranial and extracranial vessels.
The contractile effect of 5-HT on intra- and extracranial arteries from rabbit, cat, dog and man and its interaction with methysergide was investigated. ED50 and EAm values for 5-HT from both types of arteries differed. Intracranial arteries stimulated by 5-HT were more sensitive to methysergide than extracranial arteries. In intracranial vessels the methysergide antagonism is non-competitive while in extracranial it is competitive. These differences might suggest a heterogeneity of 5-HT receptors located within the cranial circulation.
D000818:Animals; D002415:Cats; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004285:Dogs; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008784:Methysergide / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology; D013045:Species Specificity
D011985:Receptors, Serotonin; D012701:Serotonin; D008784:Methysergide