Abstract:

BACKGROUND: On-pump beating-heart technique has been promoted as better systemic protection compared with the technique of cardioplegic arrest, and the attenuated inflammatory reaction may play an important role in the protective effect of the on-pump beating-heart technique.
OBJECTIVE: To observe the protective effects of St. Thomas No.2 solution supplemented with levocarnitine on preservation of hypothermic rat hearts ex vivo.
METHODS: Isolated rat heart Langendorff model and working model were established. Thirty-two Sprague-Dawley rats were randomized to four groups with eight rats in each group. In two groups, the hearts were arrested with St.Thomas No.2 solution and preserved in the same solution for 4 hours or 6 hours, while in the other two groups, the hearts were arrested with St.Thomas No.2 solution supplemented with levocarnitine (12 g/L) and preserved in the same solution for 4 hours or 6 hours.
RESULTS AND CONCLUSION: Compared with St. Thomas No.2 solution group, after the hearts were preserved for 4 hours, there were no differences in heart rate, coronary artery flow, left ventricular systolic pressure peak, +dp/dt max, water content in myocardium, and adenosine triphosphate (P > 0.05), but creatine kinase release was significantly reduced (P < 0.05) in the St.Thomas No.2 solution supplemented with levocarnitine group. After the hearts were preserved for 6 hours, the measurement results above-mentioned were superior in the St.Thomas No.2 solution supplemented with levocarnitine group than in the St.Thomas No.2 solution group (P < 0.05). These results suggest that St.Thomas No.2 solution supplemented with levocarnitine provides better effects on preservation of hypothermic rat hearts ex vivo.