Accumulation of polymorphonuclear leukocytes during 3-h experimental myocardial ischemia

Abstract

Recent evidence indicates that mechanical obstruction of capillaries by leukocytes plays an important role in the "no-reflow" phenomenon in the heart. This entrapment of leukocytes in the microcirculation precedes their recognized role in an inflammatory reaction following ischemia. It is a fundamental rheological mechanism that may be associated with ischemic injury and reflow injury and it has not been elucidated. To explore the accumulation of granulocytes during myocardial ischemia we studied the accumulation of 111Inlabeled autologous granulocytes in acutely ischemic myocardium during 3 h of flow reduction with and without a subsequent period of reflow in open-chest dogs. Granulocytes accumulated in the ischemic endocardium of all animals and, for the majority of dogs, also in the epicardium. Accumulation in the endocardium was enhanced by reperfusion. The entrapped leukocytes may have an influence on the increase in resistance, since regional accumulation of leukocytes in the endocardium inversely correlated with ischemic blood flow during 3 h of ischemia. The tissue water content measured from the wet and dry weights of biopsies showed a significant positive correlation with the number of entrapped granulocytes. These results suggest that collateral flow is an important mechanism of leukocyte arrival early in ischemic myocardium and that reperfusion enhances granulocyte accumulation.

Multiparticle adhesive dynamics: Hydrodynamic recruitment of rolling leukocytes

“…Kopaniak et al (9) quantified the accumulation of neutrophils at the site of intradermal injection of killed Escherichia coli, showing a peak of 7,000 cells per site after 2.5 h and a decrease to zero adhesion after 6 h. Leukocyte accumulation also is associated with ischemia conditions. In a dog model of myocardial ischemia, Engler et al (10) found via direct histological measurements that leukocytes accumulate early but that the great majority of granulocytes is still intravascular during 1, 3, and 5 h of ischemia. Granger et al (11) quantified the accumulation of adherent leukocytes during ischemiareperfusion in cat mesentery.…”

Leukocyte-depleted Continuous Blood Cardioplegia for Coronary Artery Bypass Grafting

“…[3][4][5] Furthermore, polymorphonuclear leukocytes have been implicated as a major effector of reperfusion injury. 5) It has been reported that the removal of neutrophils at the time of reperfusion improves functional recovery [8][9][10] and myocardial function. 8,9) In addition, leukocyte depletion of the perfusate attenuates reperfusion injury 10) and prevents ultrastructural damage.…”

“…5) It has been reported that the removal of neutrophils at the time of reperfusion improves functional recovery [8][9][10] and myocardial function. 8,9) In addition, leukocyte depletion of the perfusate attenuates reperfusion injury 10) and prevents ultrastructural damage. [5][6][7][8][9][10][11] Conversely, other studies have shown that the neutrophil content of the stunned myocardium is not increased and that interventions that remove neutrophils do not improve function.…”

“…8,9) In addition, leukocyte depletion of the perfusate attenuates reperfusion injury 10) and prevents ultrastructural damage. [5][6][7][8][9][10][11] Conversely, other studies have shown that the neutrophil content of the stunned myocardium is not increased and that interventions that remove neutrophils do not improve function. 12,13) Previous studies have demonstrated that the use of a leukocyte removal filter in the extracorporeal circuit does not affect the clinical outcome.…”

“…20) Leukocyte depletion during reperfusion has been shown to attenuate endothelial reperfusion injury. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] Endothelial function is mediated via nitric oxide. Nitric oxide synthesis by the endothelium inhibits platelet adhesion, neutrophil adhesion, homotypic aggregation, and superoxide formation.…”