[Cardioprotective effects of cariporide as an adjunct in different cardioplegic solutions: an experiment with rabbits].

OBJECTIVE

To investigate the cardioprotective effects of cariporide as an adjunct in different cardioplegic solutions.

METHODS

The hearts of 32 young New Zealand rabbits were isolated, hung on the Langendorff perfusion apparatus, arrested with 4 degrees C cardioplegic solutions to cause cardiac ischemia for 120 min, reperfused with 37 degrees C Krebs-Henseleit solution, and randomly divided into 4 equal groups: St. Thomas cardioplegic solution group (perfused with St. Thomas cardioplegic solution every 30 min), histidine-tryptophane-ketoglutarate (HTK) cardioplegic solution group (perfused with HTK solution, St. Thomas solution + cariporide (St + C) group (perfused with St. Thomas cardioplegic solution plus cariporide), and HTK solution plus cariporide (HTK + C) group (perfused with HTK cardioplegic solution plus cariporide). Multichannel physiological record instrument was used to record the left ventricular functions: left ventricular diastolic pressure (LVDP), maximum change rate of left ventricular systolic pressure rise and fall (+dp/dt(max)), maximum change rate of left ventricular diastolic pressure rise and fall (-dp/dt(max)), and coronary flow (CF). Automatic biochemical analyzer was used to measure the creatine kinase (CK)-MB, Then the level of ATP in the cardiac muscle cells was detected by high pressure liquid chromatography, the content of malonyldialdehyde (MDA) was detect by sulfur barbituric acid method. The calcium content (iCa) was measured by atomic absorption spectrophotometry. And the myocardial water content (WC) was measured too.

RESULTS

The LVDP, +dp/dt(max), -dp/dt(max), CF recovery rate, and ATP content of the HTK group were all significantly higher than those of the St. Thomas group (all P < 0.05), and the CK-MB, MDA, WC, and iCa of the HTK group were all significantly lower than those of the St. Thomas group (all P < 0.05). The ATP level of the HTK + C group was significantly higher than those of the HTK and St + C groups (both P < 0.05), and the CK-MB, WC, MDA, and iCa of the HTK + C group were all lower than those of the HTK and St + C groups (all P < 0.05). The MDA level of the St + C group was significantly higher than that of the HTK group, and the ATP of the St + C group was significantly lower than that of the HTK group (both P < 0.05), however, there was no significant differences in CK-MB, WC, and iCa between these 2 groups (all P > 0.05).

CONCLUSION

Cariporide enhances the cardioprotective effects of the St. Thomas and HTK cardioplegic solutions in immature myocardium.