预处理早发和延迟时相重叠保护心脏的实验研究(英文)

Experimental study of influences of delayed and early preconditioning on heart preservation

目的 探讨以单磷酯A预处理的延迟时相与以腺苷预处理的早发时相重叠对心脏保护效果的影响。方法 大白兔以单磷酯A预处理24h后制成离体心脏,再以腺苷预处理(MA)组,4℃改良St.Thomas液诱导心脏停搏低温保存4h,复灌1h。观察心功能恢复率、心肌ATP和MDA含量、Ck-mb释放量等。另设单磷酯A预处理延迟时相(M组)、腺苷预处理早发时相(A组)、单纯改良St.Thomas液保护(C)组。结果 MA、A、M、C组的心功能恢复率(+10-3μmol/wet·gmax,%)分别为(70.97±17.92),(64.36±16.10),(65.54±22.62)和(39.07±13.78),MA组高于A、M、C组,并与C组的差异有显著性(P<0.01)。MA组心肌ATP含量(10-3Llmol/wetg)为(5.46±1.37),高于M组(3.97±1.04)、C组(2.07±0.74)和A组(4.45±1.29),差异有显著性(P<0.05或P<0.01)。结论 以腺苷预处理的早发时相与单磷酯A预处理的延迟时相重叠可以部分增强心脏保护作用。

Objective: To study the potential additive improvement of donor heart storage by combination of delayed and early preconditioning. Methods:Rabbits were divided into 4 groups randomly, then monophosphoryl lipid A was used to achieve delayed preconditioning in group MA and group M, and adenosine was utilized to induce early preconditioning in group MA and group A, while group C was preserved with 4 ℃ St. Thomas solution as control. Using Langendorff apparatus and isolated crystalloid-perfused heart model, the hearts were stored in St. Thomas solution at 4～6 ℃ for 4 h and reperfused with 37 ℃ oxygenated Krebs-Henseleit solution for 60 min, and the left ventricular function, myocardial CK-Mb leakage, tissue levels of adenosine triphosphate and malondialdehyde were measured. Results:The left ventricular function recovery rate as percentage(+dp/dt max) in groups MA, M and A were (70.97±17.92), (64.36±16.10) and (65.54±22.62), respectively, and much better than that of group C \[(39.07±13.78)\], and the differences were significant ( P <0.01). Myocardial ATP content in group MA was much higher than that in group A, C and M ( P <0.01 or P <0.05). Conclusion: Myocardial delayed preconditioning with MLA can be partially enhanced by the early preconditioning with adenosine and has more beneficial effects on heart preservation.