Effects of lipoteichoic acid induced delayed preconditioning on ischemia-reperfusion injury in isolated rat hearts.

To explore the potential of lipoteichoic acid (LTA) induced cardioprotection against ischemia-reperfusion (I/R) injury in isolated rat hearts and whether endogenous nitric oxide (NO) participates in the protection, the rats were pretreated with LTA (1 mg/kg, i.p.) 24 h before the experiment, and the isolated hearts were subjected to 30 min no-flow normothermic global ischemia and 60 min reperfusion after a 20-min stabilization period by the langendorff method. Cardiac functions were evaluated at the end of stabilization, and at 30 min, 60 min of reperfusion. The amounts of MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase(LDH) and total NO oxidation products in the coronary effluent were measured spectrophotometrically at the end of reperfusion. It was revealed that pretreatment with LTA could significantly improve the recovery of cardiac function, reduce the release of CK-MB and LDH, and increase the concentrations of NO in coronary effluent. The protective effects were abrogated by pretreatment of the rats with L-NAME. It was concluded that LTA could induce the delayed cardioprotection against I/R injury, and endogenous NO may be involved in the mechanisms.