Immunocytochemical study with anti-muscle actin antibody (HHF35) on myocardial ischaemia and reperfusion injury in rats.

Myocardial ischaemia and reperfusion injury in 16 anaesthetized Sprague-Dawley rats, eight of which were pretreated with morphine (5 mg/kg, intraperitoneally) to prevent arrhythmias, were studied immunocytochemically with anti-muscle actin specific monoclonal antibody (HHF35). Eight cases of simple ischaemia and eight cases of sham-operated rats were used as controls. With HHF35 ABC immunocytochemical method, the left ventricular myocardium in the reperfusion group (without morphine) showed large areas of staining loss, but no loss of staining was seen in controls. No significant changes were seen with H&E stain in all hearts. Compared with HBFP, acridine orange (AO), eosin-fluorescence, HHF35 ABC staining best demonstrated myocardial reperfusion injury. The results indicate that the degree of myocardial damage may be related to the arrhythmias.