Integrins and monocyte migration to the ischemic myocardium.

ABSTRACTAims: Characterize mononuclear cell migration after acute-myocardial infarction (MI).Material and Methods: Male Lewis rats underwent a left thoracotomy and ligation of the left anterior descending coronary artery (MI group). Control animals underwent thoracotomy without ligation (Sham group). Animals were sacrificed at 0, 2, 4, or 24 hr after the onset of ischemia. Leukocyte migration was assessed using isolated and In111 labeled mononuclear cells (injected at the onset of ischemia) and γ-count determined at 24 hours. Inhibition of migration was evaluated with monoclonal anti α4 and/or β2 antibodies. Results: Serum troponin was significantly elevated in animals with MI as compared with Sham (p = .017). Labeled mononuclear cell migration was five-fold higher in MI-treated animals than in Sham (p = .006). ED-1 positive mononuclear cells were confirmed in the left myocardium after 24 hr of ischemia. MCP-1 mRNA was significantly elevated in the left myocardium at 2 hr and 4 hr and peaked at 24 hr (p <...