Pharmacological characterization of a vasopressin V1 receptor in the isolated human gastric artery.
Species-related specific differences in the pharmacological profile of vasopressin V1a receptors have been reported. Thus, the aim of the present study was to identify a vascular preparation of human origin expressing V1a receptors. Vasopressin was found to contract human gastric artery strips without endothelium with high affinity (pEC50 8.9). The maximal effect induced by vasopressin was inversely related to the diameter of the vessel. Oxytocin was found to contract the human gastric artery strips with low potency (pEC50 7.2). Contraction induced by vasopressin was competitively antagonized by the non peptide vasopressin receptor antagonists SR 49059 (pA2 9.2), OPC 21268 (pA2 6.2) and OPC 31260 (pA2 7.1). The order of potency of agonists (vasopressin > > oxytocin) and of antagonists (SR 49059 > > OPC 31260 > OPC 21268) indicate the contraction induced by vasopressin in the isolated human gastric artery is mediated by the V1a receptor type. The present data are similar to those obtained in different preparations expressing the native human V1a receptor as well as to those obtained in cell transfected with this receptor. The human gastric artery is a monoreceptor system of great utility for studying the effects of new drugs interacting with the human V1a receptor.
Calò
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Institute of Pharmacology, University of Ferrara, Italy.
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Traina
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D000368:Aged; D000369:Aged, 80 and over; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001158:Arteries / Q000187:drug effects; D001552:Benzazepines / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology; D017483:Receptors, Vasopressin / Q000819:agonists / Q000378:metabolism*; D013270:Stomach / Q000098:blood supply*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines; D007211:Indoles; D010880:Piperidines; D011759:Pyrrolidines; D015363:Quinolones; D017483:Receptors, Vasopressin; D014662:Vasoconstrictor Agents; D001127:Arginine Vasopressin; C068644:OPC 21268; C076251:mozavaptan; D010121:Oxytocin; C082134:relcovaptan