高原慢性低氧对大鼠离体心脏缺血再灌注损伤的影响

目的 观察高原低氧对大鼠离体心脏缺血再灌注损伤的影响.方法 Wistar大鼠20只,随机分为低氧组和常氧组,每组10只.前期将低氧组大鼠置于低压氧舱内（5 000米,24h/d,维时20天）,制作慢性低氧模型;后期应用 Langendorff离体心脏灌注系统进行大鼠离体心脏缺血再灌注,记录稳定灌注期及复灌期1、5、10 min及复灌末系统灌注压、心脏LVSP、dp/dt max 和 -dp/dt min及心率等的变化情况,并收集稳定期及复灌期灌流液以备测CK、LDH等心肌酶学变化,最后留取心脏标本行组织病理学观察.结果 低氧组较常氧组：心脏LVSP、dp/dt max 和 -dp/dt min升高明显（P＜0.05）、心率下降、心肌酶学指标升高显著（P＜0.05）.心脏形态学变化明显.结论高原慢性低氧对大鼠离体心脏缺血再灌注损伤存在影响.

THE INFLUENCE OF ALTITUDE CHRONIC HYPOXIA ON ISOLATED RAT HEART ISCHEMIA-REPERFUSION INJURY

Objective To observe the influence of altitude hypoxia on isolated rat heart ischemia-reperfusion injury.Methods 20 Wistar rats were randomly divided into hypoxic and normoxic group,n=10.The pre-hypoxic rats placed in a hypobaric chamber（5000m,24h/d,20days）to establish the model of chronic hypoxia;the Langendorff isolated heart perfusion system was used to carry on isolated rat heart ischemia-reperfusion and then record systems perfusion pressure,heart LVSP,dp/dt max and -dp/dt min and the changes of heart rate at stability and reperfusion period 1,5,10 min and perfusion end;The each stage perfusion fluid of stable and reperfusion period was collected for detecting the cardiac enzymes such as CK,LDH.Finally heart specimens was taken for observing the cardiac histopathological changes.Results The cardiac LVSP,dp/dt max and -dp/dt min was increased significantly in hypoxic group compared with normoxic group（P〈0.05）.In hypoxic group,the heart rate declined and cardiac enzymes increased significantly（P〈0.05）as well.The cardiac morphology changed obviously in hypoxic rats than normoxic ones.Conclusion The altitude chronic hypoxia can influence on isolated rat heart ischemia-reperfusion Injury.