单磷酯A预处理延迟效应保护心脏的实验研究

Experiment Study of Protecting Heart by Delayed preconditioning with Monophosphoryl Lipid A

目的：探讨单磷酯 A 预处理延迟效应保护心脏的效果。方法：M 组大白兔以单磷酯 A 预处理24h 后制成离体心脏，4℃心麻液诱导心脏停搏，该液中低温保存4h，复灌1h。观察心功能恢复率、心肌 ATP 和 MDA 含量及 Ck-mb 释放量，并与单纯心麻液保存的 C 组比较。结果：M 组左室压力上升、下降最大速率恢复率(±dp/dtmax，%)、ATP 含量(10^(-3)μmol/wet g)分别为65.54±22.62，68.12±18.14，3.97±1.04，而 C 组分别为39.07±13.78，35.47±14.37，2.06±0.73，差异均有显著性(P＜0.01)。结论：单磷酯 A 预处理的延迟效应对心脏具有保护作用。

Objective To study the potential improvement of donor heart storage by monophosphoryl lipid A (MLA) precon-ditionin.Methods Rabbits were injected MLA or vehicle,and 24 hours later,the hearts were isolated and mounted on a Langendorffapparatus,perfused with filtered modified Krebs-Henseleit (K-H) buffer throught left atria,instrumented left ventricular functionmonitor system and paced ventricularly at 180 beats/min.Hearts then were arrested with 10℃ modified St.Thomas solution,storedfor 4 hours at 4℃ in this solution,and repeffused with K-H buffer.The left ventricular function,myocardial CK-mb leakage andtissue levels of ATP and MDA were measured.Results The hearts preconditioned with MLA had better function expressed as recoverypercentage (+ dp/dt max 65.54±22.62),which was significantly different from that (39.07±13.78) in the control group (P<0.01).Conclution This study suggests the transient preconditioning with MLA may trigger myocardial delayed reaction and has somebeneficial effects on donor heart preservation.