title: Neurohypophysial peptide interaction with magnesium in avian vascular smooth muscle.
abstract: 1. The contractile responses of helically cut vascular strips of chickens to vasoactive agents were studied.2. Large pulmonary arteries were contracted by neurohypophysial peptides, but not by angiotensin, acetylcholine, histamine, 5-hydroxytryptamine, bradykinin or eledoisin. The activity of oxytocin was greater than that of arginine vasopressin.3. Vasodilator effects of oxytocin upon small (200-500 mu diameter) mesenteric and muscular arteries were demonstrable, but inconsistent.4. Magnesium potentiated in a parallel fashion the vasoconstrictor effects of oxytocin and of arginine vasopressin.5. Deamino-oxytocin was potentiated by magnesium. This finding suggests a difference between the peptide-protein interactions of tissue receptors and those of neurophysin.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002645:Chickens; D004357:Drug Synergism; D004600:Eledoisin / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008638:Mesenteric Arteries / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010121:Oxytocin / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010904:Pituitary Gland, Posterior / Q000502:physiology*; D011651:Pulmonary Artery / Q000187:drug effects*; D011667:Pulmonary Veins / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects; D014667:Vasopressins / Q000494:pharmacology
chemical_list: D010455:Peptides; D014667:Vasopressins; D000804:Angiotensin II; D012701:Serotonin; D010121:Oxytocin; D004600:Eledoisin; D006632:Histamine; D008274:Magnesium; D000109:Acetylcholine; D001920:Bradykinin