title: Vascular smooth muscle serotonin and alpha-adrenoceptors.
abstract: Rat isolated perfused tail arteries were used to investigate interactions between serotonin receptors and alpha-adrenoceptors. Ketanserin was shown to be a potent serotonin antagonist (pA2 = 9.17, s.e.m. = 0.06, n = 6) which also antagonized phenylephrine (pA2 = 7.47, s.e.m. = 0.10, n = 4) and noradrenaline (pA2 = 7.55, s.e.m. = 0.14, n = 6). Ketanserin reduced the maximal response to serotonin but not to phenylephrine or noradrenaline. Prazosin antagonized phenylephrine (pA2 = 9.60, s.e.m. = 0.12, n = 5) and noradrenaline (pA2 = 9.14, s.e.m. = 0.11, n = 6) and had no effect on maximal responses. Prazosin reduced the maximal response to serotonin but did not displace the dose-response curve. These results are interpreted to indicate the existence of separate, but overlapping, serotonin and alpha-adrenoceptors.
mesh_terms: D000818:Animals; D001158:Arteries / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology*
chemical_list: D011942:Receptors, Adrenergic, alpha; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists