经二氮嗪强化的Celsior液延长大鼠供心冷保存时间的研究

Improved preservation of the rat heart with Celsior solution supplemented with Diazoxide

目的研究经二氮嗪强化的Celsior液对延长大鼠供心冷保存时间的作用及机制。方法选取近交系雄性SD大鼠作为心脏移植的供、受者。根据供心保存液的不同分为对照组和实验组，每组24只。再根据供心保存时间的不同，将对照组和实验组各随机平均分为3组：对照5、8和10 h组，分别将供心置于低温单纯Celsior液中保存5、8和10h；实验5、8和10h组，分别将供心置于含30μmol／L二氮嗪的低温Celsior液中保存5、8和10h。各组供心在保存相应时间后进行大鼠颈部异位心脏移植。术后观察和比较各组供心移植后的复跳率、心肌丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性、ATP酶活性、Caspase-3蛋白的表达水平、心肌细胞凋亡以及心肌超微结构的变化。结果供心血流开放30s内，实验8和10h组心脏复跳率较相应对照组显著提高；在相同保存时间下，实验组较对照组心肌MDA含量明显降低、SOD活性和心肌ATP酶活性明显增强以及Caspase-3蛋白表达和心肌细胞凋亡减少；各实验组和对照5h组心肌超微结构清晰、完整；对照8和10h组心肌超微结构受到不同程度的损伤。结论经二氮嗪强化的Celsior液能够有效延长大鼠供心的冷保存时间，其作用机制可能与二氮嗪减轻供心的缺血再灌注损伤有关。

Objective To investigate whether the addition of Diazoxide （DE）, a mitochondrial ATP-sensitive potassium channel （Mito-KATPC） opener, to a commercial preservation solution （Celsior） improved and extended cardiac preservation. Methods The modified Heron＇s technique for heterotopic cervical cardiotransplantation in rats was used. The donor rat hearts were stored in 4 C Cetsior cardioplegia solution with or without DE （30 μmol/L） for 5, 8, and 10 h respectively before transplantation. The restorative rate of heartbeat in 30 s after transplantation was observed. We measured the content of malonialdehyde （MDA）, the activities of superoxide dismutase （SOD）, Na^＋ - K^＋-ATPase and Ca^2＋ -ATPase, the expression of Caspase-3 proteins. And apoptotic cardiomyocytes were detected by TdT-mediated dUTP nick end labeling （TUNEL） technique. The myocardial uhrastructure was also determined. Results At the same time of hypothermic preservation the DE group was much superior than the Celsior group in most indexes. The restoration rate of heartbeat in 30 s after transplantation in DE group was significantly increased as compared with the Celsior group except 5 h group. DE significantly decreased the content of MDA, enhanced the activities of SOD, Na^＋ -K^＋ -ATPase and Ca^2＋ -ATPase, also reduced the expression of Caspase-3 proteins and apoptosis index. There was no significant difference beween DE 10 h group and Celsior 5 h group with any index. The myocardiac histological change showed better in DE groups and Celsior 5 h group. Conclusion These results indicate that the Celsior solution supplemented with DE extends the safe period of storage of the rat heart, which may be related to the alleviation of ischemia-reperfusion injury of the donor heart by DE.