Vasopressin-induced contraction in the rat basilar artery in vitro.
Vasopressin ([Arg(8)]vasopressin)-induced contraction was characterized using receptor agonists and antagonists for vasopressin and channel blockers in the rat basilar artery ring preparations. Vasopressin induced rhythmic contractions superimposed on a contraction in endothelium-intact preparations but not in denuded ones. Endothelium removal shifted the concentration-response curve for vasopressin leftward and upward. In endothelium-denuded preparations, vasopressin V(1) receptor antagonist shifted the concentration-response curve for vasopressin downward and rightward. Vasopressin V(1) receptor agonist caused contraction but V(2) receptor agonist did not. The contractile response to vasopressin was partly inhibited by nifedipine, SK&F 96365 (1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole) and niflumic acid. In the absence of extracellular Ca(2+), vasopressin produced a transient contraction. Charybdotoxin produced an upward and leftward shift of the concentration-response curve for vasopressin. These results suggest that vasopressin elicits contraction due to Ca(2+) influx through voltage-dependent and receptor-operated Ca(2+) channels and to Ca(2+) release from Ca(2+) stores by activating vasopressin V(1) receptors in the rat basilar artery.
Katori
E
E
Laboratory of Pharmacology, Graduate School of Veterinary Medicine, Hokkaido University, 060-0818, Sapporo, Japan.
Ohta
T
T
Nakazato
Y
Y
Ito
S
S
D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001030:Apamin / Q000494:pharmacology; D001488:Basilar Artery / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000494:pharmacology; D018999:Charybdotoxin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000819:agonists; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects; D014667:Vasopressins / Q000494:pharmacology*
D065092:Antidiuretic Hormone Receptor Antagonists; D007093:Imidazoles; D017483:Receptors, Vasopressin; D014667:Vasopressins; D018999:Charybdotoxin; D001030:Apamin; D011189:Potassium Chloride; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D002118:Calcium