Abstract: Objective To observe the combined protective effects of U50 488H and hypothermia preservation on isolated rabbit hearts preconditioned. Methods Forty rabbits were randomly divided into five groups, 8 rabbits in each group. The perfusion model of isolated rabbit hearts was established by the Langendorff device. In the control group: the isolated rabbit hearts were preserved with the University of Wissconsin solution (UW ) for six hours; groupI : the isolated rabbit hearts were preconditioned with St. ThomasII cardioplegic solution containing U50 488H (1. 6mmo l/L ) and then preserved with hypothermic preservation for four hours; groupII ; the precondition was the same as group II , hypothermic preservat ion fo r six hours; group III : the precondit ion was the same as group I , hypothermic preservation for eight hours; group IV : the precondit on was the same as group I , hypothermic preservation for ten hours. The cardiac function, myocardial sarcoplasmic reticulum calcium ion adenosine triphosphatase (SRCa2+ -ATPase) act ivity and calcium ion concentrations in mitochondria were determined at thirty minutes after reperfusion. Results As the hypothermic preservation time increased from four to ten hours, the recovery rate of each index of cardiac function, coronary artery flow (Cf) and SRCa2+ -ATPase activity also decreased, but the calcium ion concentrations in the mitochondria increased. Cardiac function index recovery rates in group I and group II w ere higher than those in group III and groupIV respectively (P lt; 0. 05, 0. 01) ,meanwhile recovery rates of cardiac function index in group III were higher than that in group IV (P lt; 0. 05). Recovery rate of Cf in groupII ( 84. 56%±10. 38%)were higher than those in group III (79. 45%±9. 67% ) and group IV (68. 31%±6. 84% , P lt;0.01) , meanwhile the recovery rate of Cf in group III was higher than that in group IV (P lt; 0. 05). SRCa2+ -A Tpase activity in group II (4. 43±0. 41μmo l/m g?h)were higher than those in control group (3. 04±0. 22Lmo l/mg?h ) , group III (3. 26±0. 29Lmo l/m g?h) and group IV (2. 57±0. 63Lmo l/m g?h, P lt; 0. 05) , SRCa2+ -ATPase activity in group III was higher than that in group IV (P lt; 0. 01). The calcium ion concentrations in mitochondria in group II (38176±4. 30μmo l/g ?dw ) and in the control group (40. 23±3. 75μmol/g ?dw )were less than those in group III (43125±5116μmol/g?dw ) and groupIV (45. 78±3. 26μmol/g?dw , P lt; 0. 05, 0. 01) respect ively. Conclusion The hypothermic preservation time for isolated dono r’s hearts p re-treated with St. Thomas II cardioplegic solution containing U 50 488H should the kep tunder 8h. The myocardial protection effects of both UW solution and U50 488H- containing St. Thomas II cardioplegic solution on isolated dono r’s hearts appear to be the same at 6 hours.
Citation： DUAN Daw ei,LI Tong,HU Xiaom in,ZHU Hailong,LIU Jian,ZHANG Qiang,WU Peng,LANG Yuheng. The Combined Protective Effects of U50 488H and Hypothermia Preservation on Isolated Rabbit Hearts. Chinese Journal of Clinical Thoracic and Cardiovascular Surgery, 2008, 15(1): 44-47. doi: Copy