七氟烷缺血后处理对离体大鼠心肌细胞的保护作用

Cardioprotection of sevoflurane postconditioning on isolated rat hearts

目的观察七氟烷缺血后处理对离体大鼠心肌细胞凋亡的影响。方法20只♂Wistar大鼠随机分为缺血对照组(A组)和七氟烷缺血后处理组(B组),每组10例。两组离体鼠心均用Langendorff离体心脏灌注模型,以改良Kreb-Henseleit液灌流平衡20min后,停灌40min,再灌注60min。B组在复灌时以平衡有1.0Mac的七氟烷灌注液灌注15min。以Powerlab Chart 5软件动态监测左室展压(LVDP)、左室压力变化最大速率(±dp/dtmax),心率(HR)。计量平衡20min、复灌15min和复灌60min的冠状动脉灌注流量(CF)。以2,3,5-氯三苯四唑染色(TTC)染色心肌切片,并以Image J 1.37软件计算心肌梗死面积。TUNEL法检测染色凋亡细胞,尼康高倍光学显微镜(Nikon Eclipse,E400,日本)视野拍照并存档,以Leica Qwin Plus V3软件分析,计算凋亡指数(AI)。结果和A组比,B组复灌后的LVDP、±dp/dtmax、CF和HR均明显升高(P<0.05);B组复灌后心梗面积明显减小且AI明显降低(P<0.05)。和基础值比,复灌15min以及复灌60min的LVDP、±dp/dtmax、CF和HR均显著降低(P<0.05)。结论七氟烷缺血后处理抑制离体大鼠心肌的细胞凋亡,提示对缺血再灌注(I/R)心肌具有心肌保护作用。

Aim To observe the protective effect of sevoflurane on reperfused myocardium of isolated rat hearts. Methods 20 male Wistar rat hearts were isolated, linked to a Langendorff apparatus and randomly divided into 2 groups：control group （group A ）, and sevoflurane postconditioning group（ group B）. Isolated perfused rat hearts were exposed to 40 min of ischemia followed by 60 min of reperfusion with modified KrebHenseleit （ K-H ） buffer. Anesthetic postconditioning was induced by 15 min of 1.0 Mac sevoflurane administered at the onset of reperfusion. The left ventricular developed pressure（LVDP） , and the maximum rate of increase or decrease of left ventricular pressure （ ± dp/ dtmax） were recorded at the end of the stabilization period, 15 min and 60 min after reperfusion. Infarct size was determined by 2, 3, 5-triphenyhetrazolium chloride staining. Myocardial TUNEL staining was used in situ cell death detection kit （POD, Roche, Germa- ny）. The percentage of TUNEL positive nuclei to all nuclei counted was used as apoptotic index （AI）. Resuits Compared with those of group A, the data of hemodynamics of LVDP, ±dp/dt CF and HR of group B were significantly higher but the infarct size and AI of group B were much lower during reperfusion period than those in group A （ P 〈 0. 05 ）. Compared with baseline value, the data of LVDP, ± dp/dt CF and HR decreased significantly in both groups （P 〈 0. 05）. Conclusion Anesthetic postconditioning by sevoflurane effectively protected against reperfusion damage by preventing myocardial apoptosis in rat hearts.