摘要
目的 研究急性低氧和间断低氧习服对大鼠离体心脏缺血 /再灌注损伤的影响。方法 经间断低氧习服 (模拟海拔 30 0 0m ,5 0 0 0m低氧 2周 ,每天 4h ,最后 80 0 0m低氧 4h)和急性低氧 (模拟海拔 80 0 0m低氧 4h)的大鼠 ,麻醉后开胸 ,迅速取出心脏 ,观察其离体心脏缺血 /再灌注损伤情况。结果 离体心脏缺血 /再灌时的心率在第 3min时最低 ,以后逐渐恢复 ,低氧习服组和急性低氧组的心率可恢复至缺血前水平 ,显著高于常氧对照组。反映心脏收缩功能的指标左心室收缩压 (LVSP)和 +dp/dtmax及反映心脏舒张功能的指标 -dp/dtmax在复灌的第 3～ 5min时降至最低 ,心脏功能损伤较重 ,以后逐渐恢复。其中低氧习服组大鼠离体心脏的LVSP、+dp/dtmax和 -dp/dtmax显著高于常氧对照组和急性低氧组。冠脉流出液中的肌酸磷酸激酶 (CPK)亦在缺血 /再灌后显著升高 ,且有不断升高的趋势 ,低氧习服组的CPK含量显著低于常氧对照组和急性低氧组。结论 低氧习服可减轻大鼠离体心脏的缺血 /再灌损伤。
Objective To study the effects of acute hypoxia and intermittent hypoxic acclimatization(HA) on ischemia/reperfusion(I/R) injury in isolated working hearts of rats. Methods The contractive and diastolic functions of isolated working hearts during ischemia and reperfusion were investigated in rats after intermittent hypoxic acclimatization(HA) (3000 m and 5000 m, 2 weeks respectively, 4 h/d) and in normoxic rats(NXR) exposed to hypoxia (8000 m) for 4 h(AHR). Results The heart rates(HR) of isolated working hearts were reduced to the minimum at the third minute after reperfusion and restored gradually later. The HR of acute hypoxic rats(AHR) and HA rats could be restored to the levels before ischemia and were higher than that of NXR significantly. Generally, the parameters of cardiac contracting function LVSP and +dp/dt maxand parameter of diastolic function -dp/dt maxwere reduced to the minimum at the third or fifth minute after reperfusion and restored gradually later. The LVSP, +dp/dt maxand -dp/dt maxof isolated working hearts derived from HA rats were higher than those of NXR and AHR. The activity of creatine phosphokinase (CPK) in coronary effluent was increased significantly after ischemia/reperfusion and had the gradual increasing tendency. The activity of CPK in HA rats was lower than that in NXR and AHR. Conclusion These results suggest that HA can alleviate the ischemia/reperfusion injury of isolated working hearts.
出处
《中华老年多器官疾病杂志》
2004年第2期120-123,共4页
Chinese Journal of Multiple Organ Diseases in the Elderly
基金
国家自然科学基金重点项目 (№ 3 973 0 190 )
全军医药卫生科研基金课题 ( 0 1Z0 2 5 )
