肝细胞生长因子对长时间保存大鼠供体心的保护作用

Experimental study of protective effect of recombinant human hepatocyte growth factor on heart graft preservation in rats

目的研究肝细胞生长因子（HGF）对大鼠供体心长时间保存的保护作用并探讨其可能作用机制。方法40只SD大鼠随机分为对照组（n=20）和实验组（n=20）。Langendorff-Neely灌注模型。分别用HTK液和HTK＋rh-HGF（100μg／L）液作为停跳液和保存液，保存8h（A组，C组）和12h（B组，D组）。通过检测保存前后的血流动力指标的恢复率；测定冠脉流出液中CK、LDH，NO、ET的变化；免疫组化测定c-met；TUNEL法检测AI；RT-PCR法检测·心肌bcl-2mRNA的表达。结果实验组血流动力学指标恢复较好（P〈0．01），心肌病理损伤减轻；冠脉流出液中CK，LDH含量降低（P〈0．01），NO活性提高（P〈0.05）；ET降低（P〈0．01）；c-met表达升高（P〈0．01）；AI降低（P〈0．01）；bcl-2mRNA的表达升高（P〈0．01）。结论HGF通过其特异性受体c-met的表达改善内皮功能，增加冠脉流量及心肌血流灌注；上调bcl-2表达，减轻供心长时间保存过程中的细胞凋亡，产生有效的保护作用。

Objective To observe the effect of hepatocyte growth factor on preserving isolated heart of rats. Methods Forty rats were random divided into two groups： Control group （ n =20） which rat hearts were isolated and preserved in 4℃ HTK solution, and experimental group （ n =20） which rat hearts were isolated and preserved in 4℃ HTK ＋ rh - HGF（ 100μg/L） solution. Before operation and rat hearts were subjected to 8 hours （group A, C） or 12 hours （group B, D） hypothermic storage followed by 5 minutes of normothermic reperfusion on modified Langendorff-Neely model. The recovery rateof cardiac function after myocardial preservation, such as LVSP and LVDP and ＋ dp/dt max and the changes of CK, LDH, NO and ET were measured. Cell apoptosis was detected by TUNEL staining and the expression of c-met was analyzed by immunohistechemical method. The expression change of bcl-2 mRNA was examined by RT-PCR. Results Compared with control group, experimental group showed that a significantly higher recovery rate of LVSP, LVDP and ±dp/dt max （ P 〈0. 01） and lower rate of TUNEL- positive cardiomyocytes （ P 〈0. 01 ） after repeffusion. The leakage of CK and LDH was significant lower than that of control group （ P 〈 0. 01 ）. Immunohistochemical analysis revealed that c-met receptor expression was stronger in the HGF-treated myocardium than that in the non HGF-treated myocardium after storage, and this was associated with a stronger expression of bcl-2 mRNA. Conclusion The administration of rh-HGF before storage improved cardiac function after prolonged myocardial preservation by preventing apoptosis and enhancing expression of bcl-2 mRNA. Thus, the addition of rh-HGF in the storage solution may be a promising strategy for prolonged heart graft preservation.