AIM AND METHODSUsing in vivo myocardial injury model induced by Isoproterenol (ISO) and the model induced by in vitro global heart ischemia/reperfusion (I/R) in rats, we observed the effects of myocardial ischemia and ischemia/reperfusion on bio-membranes of mitochondria and sarcolemma injury.

RESULTSISO (5 mg/kg, s.c.) and I/R (20 min/20 min) damaged myocardial bio-membranes of rat, in which the lipid peroxidation of mitochondria was significantly increased, the activity of phospholipase A2 was activated and the contents of phospholipid and free fat acid were decreased and increased significantly, respectively. The membrane lipid fluidity and the activities of Ca(2+) -ATPase of mitochondria and Na+, K(+) -ATPase of sarcolemma were significantly lowered. In addition, the respiration function of mitochondria was declined and the oxidative phosphorylation of respiratory chain was uncoupled, which resulted in the decrease in the production of high energy phosphoric acid compounds.

CONCLUSIONMyocardial injuries caused by ISO or I/R injured the structure and function of rat myocardial mitochondria and sarcolemma.