高晶体-高胶体渗透压混合液对大鼠体外心脏缺血再灌注损伤的作用

目的观察高晶体-高胶体渗透压混合液（HHS）在预处理与后处理的方式下对缺血再灌注的大鼠体外心脏功能和心肌组织学结构等的影响。方法雄性SD大鼠24只，复制缺血再灌注Langendorff灌流模型．随机分为对照组、预处理组和后处理组。观察各组左室发展压（LVDP）、左室舒张末期压（LVEDP）、心率-压力乘积（RPP）、冠脉流量（CF）和心率（HR）的变化。实验结束后测定左心室心肌组织过氧化物歧化酶（SOD）活性并取心尖组织电镜观察组织学改变。结果与对照组相比，预处理与后处理组心肌LVDP、RPP、CF及HR显著降低．LVEDP明显升高（P〈0．05或0．01），灌注15min后有所恢复。再灌注30min后．与对照组相比．其LVDP、RPP、CF与HR显著升高，LVEDP显著降低（P〈0．05或0．01）。预处理与后处理组的SOD活性，尤其足Mn-SOD活性明显增加。电镜结果显示对照组有大片坏死．心肌超微结构破坏严重，而预处理与后处理组表现为散在的局灶性坏死。结论HHS对体外大鼠心脏均呈现急性、负性变力变时效应．缺血后的心肌表现更为明显。但可以缓解体外大鼠心脏缺血再灌注损伤，且HHS预处理比后处理表现出更好的保护作用。

Effects of Hypertonic-Hyperoncotic Solution on Myocardial Function in Isolated Rat Hearts against Ischemia Reperfusion Injury

Objective To investigate the effects of hypertonic-hyperoncotic solution(HHS) on cardial function and myocardial histological structure in isolated rat hearts against ischemia reperfusion injury.Methods Twenty-four male rat hearts were perfused with K-H solution on a Langendorff apparatus and divided into three groups(control,pretreatment and posttreatment) randomly.LVDP,LVEDP,HR,RPP and CF were recorded continuously.At the end of reperfusion,SOD activity of left ventricular tissue was measured and myocardial histology was evaluated.Results LVDP,RPP,CF and HR were decreased and LVEDP increased significantly(P<0.05 or 0.01) in pre-and posttreatment groups as compared with control group,but restored after 15 min.Thirty min after reperfusion LVDP,RPP,CF and HR were increased and LVEDP decreased significantly(P<0.05 or 0.01) as compared with control group.HHS-pretreatment and posttreatment could increase the myocardial SOD activity,especially Mn-SOD.Morphologically,extensive necrosis and damage were observed after ischemia/reperfusion injury.Only localized myocardial necrosis was observed after HHS-pretreatment and posttreatment.Conclusion HHS-treatment showed a brief negative inotropic effect on isolated rat hearts,especially after ischemia and reperfusion injury.HHS could reduce the damage in isolated rat hearts against ischemia/reperfusion.And pretreatment with HHS showed greater protective effects.