title: Potentiation by ouabain of the response to vasoconstrictor agents of isolated dog cerebral and mesenteric arteries soaked in Ca2+-free media.
abstract: In helical strips of dog cerebral arteries soaked in Ca2+-free media and treated with prostaglandin (PG) F2 alpha or K+, the addition of Ca2+ produced a transient contraction, transient relaxation, and slowly developing, persistent contraction. Treatment with 2 X 10(-7) M ouabain did not alter the contractile response to PGF2 alpha in Ca2+-free media, but potentiated the response to Ca2+. Relaxations following the transient contractions were abolished by ouabain. On the other hand, ouabain potentiated the contractile response to serotonin in Ca2+-free media, and also the response to Ca2+. In mesenteric arterial strips soaked in Ca2+-free media, ouabain at 2 X 10(-7) M insufficient to produce contractions increased the contractile response to Ca2+, and the increase in the concentration to 2 X 10(-5) M potentiated the response to PGF2 alpha and serotonin. It may be concluded that ouabain increases the influx of Ca2+ across cell membrane caused by vasoconstrictors and enhances the drug-induced release of Ca2+ from intracellular storage sites.
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology*; D002536:Cerebral Arteries / Q000187:drug effects; D015237:Dinoprost; D004285:Dogs; D004357:Drug Synergism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D010042:Ouabain / Q000494:pharmacology*; D011460:Prostaglandins F / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D011460:Prostaglandins F; D014662:Vasoconstrictor Agents; D012701:Serotonin; D010042:Ouabain; D015237:Dinoprost; D002118:Calcium