PT - JOURNAL ARTICLE AU - M N Gillespie AU - S Kojima AU - M Kunitomo AU - M Jay TI - Coronary and myocardial effects of activated neutrophils in perfused rabbit hearts. DP - 1986 Dec 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 836--840 VI - 239 IP - 3 4099 - http://jpet.aspetjournals.org/content/239/3/836.short 4100 - http://jpet.aspetjournals.org/content/239/3/836.full SO - J Pharmacol Exp Ther1986 Dec 01; 239 AB - Studies were conducted in Langendorff-perfused rabbit hearts to assess the actions of phorbol myristate acetate (PMA)-stimulated neutrophils on coronary vascular resistance and left ventricular contraction. Whereas PMA or neutrophils alone were without effects in this preparation, PMA-stimulated neutrophils evoked pronounced increases in coronary resistance and decreases in left-ventricular pulse pressure. The changes in coronary resistance and left ventricular pulse pressure induced by PMA-stimulated neutrophils were attenuated by scavengers of superoxide anion (superoxide dismutase), hydrogen peroxide (catalase) and hydroxyl radical (dimethylthiourea), thereby implying a pivotal role for hydroxyl radical. Inasmuch as the increase in coronary resistance could be reversed partially by the nonspecific vasodilator, sodium nitroprusside, and inasmuch as none of the free radical scavengers influenced PMA-induced neutrophil aggregation, the increase in coronary resistance evoked by PMA-stimulated neutrophils is related in part to oxygen radical-mediated coronary vasoconstriction.