Effect of Ca2+-entry blockade and serotonergic antagonism on contractions of hypoxic isolated canine coronary arteries.
Lidoflazine, flunarizine, and R 51 469 antagonized contractions of isolated canine coronary arteries caused by depolarizing solution or 5-hydroxytryptamine, and the further increase in tension caused by hypoxia during such contractions. The 5-HT2-antagonist ketanserin, but not methysergide, antagonized contractions induced by 5-hydroxytryptamine, but not those by high K+; it reduced further increases in tension caused by hypoxia only during contractions caused by 5-hydroxytryptamine. Augmentation by hypoxia of coronary vasoconstriction appears to be a Ca2+-dependent phenomenon.
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D000860:Hypoxia / Q000503:physiopathology*; D066298:In Vitro Techniques; D012702:Serotonin Antagonists / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
D002121:Calcium Channel Blockers; D012702:Serotonin Antagonists