Influence of polymorphonuclear leukocytes and plasma on coronary vasomotion after ischemia

Background. The role of plasma and neutrophils in endothelial dysfunction f ollowing myocardial ischemia was investigated. Methods. Isolated rabbit hearts were perfused at constant pressure with a m odified Krebs-Henseleit solution. After a 30-minute global ischemia the hea rts were perfused at the onset of reperfusion for 10 minutes with either Na Cl (group I,n = 6), autologous plasma alone (group II, n = 5), autologous p olymorphonuclear leukocytes alone (PMN, group III, n = 6), or FMN and plasm a in combination (group IV, n = 5). Before and after ischemia the effects o f intracoronary endothelial dependent and independent vasodilation by acety lcholine (1 x 10(-7) mol/L) and glycerol trinitrate (1 x 10(-6) mol/L) were investigated. Results. A similar increase in coronary flow was induced in groups I, II, a nd III by acetylcholine and glycerol trinitrate before and after ischemia. In contrast, in group IV the endothelial dependent vasodilation was signifi cantly depressed (p < 0.05). In groups II and IV a moderate but significant reduction in the recovery of the left ventricular pressure was observed af ter ischemia and reperfusion. Conclusions. These results suggest that after myocardial ischemia, plasma i s required for neutrophil-mediated endothelial dysfunction. (C) 1999 by The Society of Thoracic Surgeons.