Failure to Reduce Infarct Size by Intracoronary Infusion of Recombinant Human Superoxide Dismutase at Reperfusion in the Porcine Heart: Immunohistochemical and Histological Analysis. Journal of Molecular and Cellular Cardiology (1991) 23, 1287-1296. We quantitatively determined the extent of infarction and contraction band necrosis in porcine hearts, and analyzed the distribution of administered recombinant human superoxide dismutase (h-SOD) in the myocardium using a polyclonal antibody to h-SOD. After 1 hour of occlusion, h-SOD was infused for the first 30 min of reperfusion in SOD group, while pigs received only arterial blood in control group. The extent of infarction or contraction band necrosis was not significantly different between SOD group and control group. Positive staining by polyclonal antibody to h-SOD was detected only in the infarcted area in SOD group. Thus, h-SOD only entered irreversibly damaged myocytes and neither diminished reperfusion injury nor reduced infarct size in pigs.