Efficacy of a Monoclonal Antibody (MoAb 60.3) in Reducing Myocardial Injury Resulting from Ischemia/Reperfusion in the Ferret

The myocardial salvage efficacy of a monoclonal antibody (MoAb 60.3) directed at the CDw 18 membrane antigen complex essential for normal neutrophil function was evaluated in a ferret occlusion/reperfusion model. When infused i. v. over a 10-min interval beginning at the 45th minute of a 90-min occlusion at a fixed dose of 2 mg/kg, the antibody afforded 33 and 45% reductions in infarct size following reperfusion intervals of 6 and 24 h, respectively. Administration of that same dose via the left atrium over 1 h beginning at the 75th minute of occulsion and continuing until the 45th minute of reflow resulted in only a 14% reduction in infarct size. If MoAb 60.3 administration was withheld until the 5th–15th minute of reperfusion, the mean levels of salvage were 19 and 8%, respectively, following 6− and 24-h periods of reflow. Timecourse hemodynamic data indicated that the monoclonal antibody caused no alterations in oxygen utilization that might be responsible for the levels of salvage observed.