EXPRESSION OF E-SELECTIN ON CORONARY ENDOTHELIUM AFTER MYOCARDIAL-ISCHEMIA AND REPERFUSION

Neutrophils localize in ischemic or infarcted myocardium and thus are implicated in playing a role in myocardial reperfusion injury and stun ning. We studied one of the mechanisms by which neutrophils are recrui ted into the region of ischemic myocardium. Anesthetized adult rhesus monkeys (n = 2) underwent ligation of one of the obtuse marginal coron ary arteries for 90 minutes followed by 5 hours of reperfusion. Tissue s from the normal perfused area of the heart and from the ischemic are a were preserved in methacarn fixative after sacrificing the animal at the end of the reperfusion period. Immunohistochemical staining showe d that E-selectin is not constitutively expressed on coronary endothel ium in vivo. E-selectin, however, was upregulated in selective endothe lial cells located in the postcapillary coronary venules in response t o ischemia and reperfusion. The presence of E-selectin in this setting suggests that it may have a similar role as in the recruitment of neu trophils into other inflamed or damaged tissues.