[Increasing myocardial tolerance of global ischemia and reperfusion injury using a synthetic peptide]

The synthetic tripeptide Tyr-Pro-Arg was tested for its cardioprotective effect when added to the cardioplegic solution or when used during reperfusion (R) after "global myocardial ischemia" (GMI). After the baseline functional parameters had been recorded, the isolated perfused hearts (IPH) from rats with the working left ventricle were subjected to 30-minute GMI at 37 degrees C. When the tripeptide was added to the cardioplegic solution (3.10(-9) M), the degree of the functional recovery of IPH was higher after GMI than when a "pure" cardioplegic solution was applied. The functional parameters of IPH were restored to a considerable extent (up to 70-100%) when the tripeptide was added to the perfusate in the same concentration during R following GMI of 30-minute duration at 37 degrees C. Without the tripeptide, the function of IPH was not restored. Thus, the synthetic analogue of the endogenous opioids, Tyr-Pro-Arg" enhances the tolerance of rat IPH myocardium to exposure to GMI and R.