The effect of supplementing hypothermic crystalloid cardioplegia with catalase plus allopurinol in the isolated rabbit heart.

The effect of adding allopurinol and catalase to hypothermic cardioplegia for ischemic-reperfusion injury was investigated in the isolated rabbit heart. Hearts were divided into two groups, namely: Group C (n = 7), which received a hypothermic crystalloid cardioplegic solution alone (4 degrees C), and group T (n = 7), which received the hypothermic cardioplegic solution with allopurinol (148 mumol/L)13 and catalase (37 nmol/L).12 The cardioplegic solution was infused continuously into the isolated hearts, which had been placed in ice-cold saline, during a 12 h preservation. Subsequently, the hearts were mounted on a noncirculating, nonpulsatile perfusion circuit using Krebs-Henseleit buffer solution at 37 degrees C for 1 h at a constant perfusion pressure of 75 mm Hg. The left ventricular developed pressure (LVDP), maximum rate of pressure change (max dp/dt), and percent recovery of coronary flow were higher, while the creatine phosphokinase concentration and left ventricular end diastolic pressure (LVEDP) were lower in group T. The tissue malondialdehyde concentration and water content were similar in both groups. Thus, cardiac function after a 12 h preservation was enhanced by the added combination of allopurinol and catalase to the cardioplegic solution, supporting its role in the prevention of free radical reperfusion injury in cardiac preservation.