Effect of L-arginine on overhydration and ultrastructure preservation of rat's heart exposed to cold cardioplegic ischaemia.

UNLABELLED: ISCHAEMIA: Reperfusion damage causes injury both cardiomyocytes and endothelial cells. Loss of endothelium function and heart cells degeneration can be essential for deterioration of postoperative efficiency of heart and in this way can threaten patients' life. OBJECTIVE: How addition of L-arginine to cardioplegic solution influences development of ultrastructural degeneration indications of rat's heart exposed to cold cardiolegic ischemia. METHODS: The research was conducted on isolated heart model of 56 rats, divided into seven equal groups. The hearts were prepared with modified Neely's method and were perfused with the use of apparatus in accordance with modified Langedorf's method. The research was carried out in order: initial perfusion of the non-working and working heart, perfusion with cardioplegic solution, cold cardioplegic arrest with or without addition of L-arginine. RESULTS: In the microscopic preparations of rat's heart in the control group (P) numerous focal performing contraction nodes were found. Intumescent vessels' endothelium included a large number of pinocytal vesicles. In the ultrastructural examination of group DI heart preparations there were less contraction nodes than in control group. The widening of endoplasmatic reticulum's channels and system T was essentially smaller comparing with group P. Less widening of perivascular zone and less number and size of pinocytal vesicles were also observed. In group 2 further decreasing of contraction nodes number was revealed. The structure of capillary was preserved and number of pinocytal vesicles was still decreasing. Further standardization of ultrastructural picture of cardiomyocytes and perivascular zone was found in group 3. CONCLUSION: In control group (P) microscopic degeneration indications of rat's heart were the most intensified. Addition of L-arginine to cardioplegic solution influenced decreasing of intensification of heart degeneration indications. Increasing of L-arginine doses added to cardioplegic solution positive correlates with protective effect of L-arginine on heart ultrastructure.