title: Halothane relaxes previously constricted isolated porcine coronary artery segments more than isoflurane.
abstract: Coronary vasodilation by halothane and isoflurane were compared using in vitro tension recording. Porcine left anterior descending coronary arterial segments (1.5-2.0 mm o.d.) were constricted with either K+ (30 mM) or prostanoid U44069 (6 X 10(-7) M) in the absence of other drugs or anesthetics. Following stabilization of constriction, arteries were exposed to halothane or isoflurane at 0.5, 1.0, 1.5, 2.0, and 3.0% concentrations. K+ (30 mM) induced constriction was reduced by halothane at 1.5, 2.0, and 3.0% and U44069 (6 X 10(-7) M) induced constriction was reduced at 0.5, 1.0, 1.5, 2.0, and 3.0%. K+ (30 mM) induced constriction was reduced by isoflurane only at 3.0% and U44069 (6 X 10(-7) M) induced constriction was reduced by isoflurane only at 2.0 and 3.0%. U44069 induced constriction was more susceptible than K+ induced constriction to relaxation by halothane or isoflurane. Halothane was more potent than isoflurane as a direct relaxant of porcine epicardial left anterior descending arterial segments previously constricted with K+ (30 mM) or U44069 (6 X 10(-7) M).
mesh_terms: D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D006221:Halothane / Q000494:pharmacology*; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology*; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D007530:Isoflurane; D006221:Halothane