甘氨酸对缺氧/复氧离体大鼠心脏功能的作用

Effect of glycine on cardiac injury induced by hypoxia-reoxygenation in isolated rat heart

目的:观察甘氨酸(glycine,GLY)对缺氧/复氧离体心脏功能的影响,探讨甘氨酸对心肌缺血-再灌注(ischemia/reperfusion,I/R)损伤的防治作用及其机制。方法:利用Langendorff灌流装置复制心肌缺氧/复氧(hypoxia/reoxygenation,H/R)模型,观察不同浓度GLY处理后心脏左室收缩压(left ventricular systolic pressure,LVSP)、左室舒张末压(left ventricular end diastolic pressure,LVEDP)、左室发展压(left ventricular developed pres-sure,LVDP=LVSP-LVEDP)、左室收缩压最大上升/下降速率(the maximum rising and dropping rates of left ventricular pressure,dp/dtmaxand dp/dtmin),并在相应的时点分别测定冠脉流出液中的超氧化物歧化酶(superoxide dismutase,SOD)活性和丙二醛(malondialdehyde,MDA)的水平。结果:H/R后各时点大鼠心功能各指标均低于缺氧前;GLY处理组复氧后心功能各指标均高于H/R组,并拮抗损伤导致的SOD减少和MDA升高。结论:一定浓度的GLY能显著改善缺氧/复氧心肌的舒缩功能,其机制可能与其提高SOD活性抑制脂质过氧化反应有关。

AIM： To observe the effects of glycine on hypoxia -reoxygenation （H/R） -induced myocardial dysfunction, and to further clarify the protection of glyeine （GLY） against myocardial isehemia/reperfusion injury and its mechanism. METHODS： A cardiac H/R model was established using a Langendorff isolated heart preparation. The left ventrieular systolic pressure （LVSP）, left ventrieular end diastolic pressure （LVEDP）, left ventrieular developed pressure （ LVDP）, the maximum rising and dropping rates of left ventrieular pressure （ dp/dtmax and dp/dtmin ） were observed. The coronary effluents at different time points were collected respectively to detect the concentration of superoxide dismutase （SOD） and malondialdehyde （MDA）. RESULTS： The indexes of cardiac functions in H/R group were lower than those in other groups. After H/R, the indexes in GLY plus H/R group were higher than those in H/R group. Glyeine inverted the effects of the decrease in SOD and the increase in MDA concentrations induced by H/R. CONCLUSION： Glyeine ameliorates the cardiac functions under the condition of hypoxia - reoxygenation injury in isolated rat hearts. The mechanisms may be related to suppressing lipid peroxidation.