论文部分内容阅读
本研究旨在探讨两种不同形式的间歇性低压低氧(intermittent hypobaric hypoxia,IHH)对发育大鼠心脏缺血/再灌注损伤的影响。雄性Sprague-Dawley(SD)新生大鼠72只,随机分为三组:对照组、IHH 3000m组(IHH3000)、IHH5000m组(IHH5000)。低氧组大鼠出生后立即于低压氧舱分别接受28d、42d和56d(海拔5000m、每天6h;海拔3000m、每天5h)的低压低氧处理。应用Langendorff离体心脏灌流技术,给予心脏缺血(停灌30min)/再灌注(复灌60min)处理,分别在缺血前5min及复灌后1、5、10、20、30、60min记录心功能和冠状动脉流量变化,并测定乳酸脱氢酶(lactate dehydrogenase,LDH)活性。实验结束时测定心脏重量。结果显示:(1)IHH3000组大鼠体重增长与对照组无明显差异;IHH5000组大鼠体重增长明显慢于对照组及IHH3000组大鼠(P<0.01)。(2)IHH3000组大鼠表现明显的心脏保护效应。与对照组相比较,在心脏停灌/再灌注60min时,心功能(LVDP、±LVdp/dtmax)恢复增强(P<0.05)、LDH活性降低(P<0.05)、冠状动脉流量增多(P<0.05);心脏重量与对照组大鼠无差异;IHH42d处理的大鼠心功能恢复明显好于IHH28d处理的大鼠(P<0.05)。(3)IHH5000组大鼠表现出明显的心脏损伤效应,各项心功能指标(LVDP、±LVdp/dtmax)的恢复均低于对照组(P<0.05),复灌过程中LDH活性明显高于相应对照组(P<0.05),右心室重量明显高于对照组大鼠(P<0.05)。结果表明,适当的IHH增强发育大鼠心脏对缺血/再灌注损伤的抵抗能力;间歇性低氧方式是影响其心脏保护作用的重要因素。
This study aimed to investigate the effects of two different forms of intermittent hypobaric hypoxia (IHH) on ischemia / reperfusion injury in developing rat hearts. Seventy - two male Sprague - Dawley (SD) male rats were randomly divided into three groups: control group, IHH 3000 mHg IHH 3000 and IHH 5000 mHH 5000. Rats in hypoxia group were exposed to hypobaric hypoxia at 28d, 42d and 56d respectively (altitude 5000m, daily 6h; altitude 3000m, daily 5h). Cardiac ischemia (ischemia 30 min) / reperfusion (reperfusion 60 min) was performed by Langendorff perfusion cardioplegia. Heart was recorded at 5 min before ischemia and at 1,5,10,20,30,60 min after reperfusion Function and coronary flow changes, and determination of lactate dehydrogenase (lactate dehydrogenase, LDH) activity. Heart weight was measured at the end of the experiment. The results showed that: (1) There was no significant difference in body weight gain between the IHH3000 group and the control group; the weight gain of the IHH5000 group was significantly slower than that of the control group and the IHH3000 group (P <0.01). (2) IHH3000 rats showed obvious cardioprotective effects. Compared with control group, cardiac function (LVDP, ± LVdp / dtmax) recovery increased (P <0.05), LDH activity decreased (P <0.05) and coronary flow increased at 60min after myocardial ischemia / reperfusion 0.05). There was no difference in heart weight between the two groups. The cardiac function recovery of IHH42d-treated rats was significantly better than that of IHH28d-treated rats (P <0.05). (3) The IHH5000 group showed obvious cardiac damage. The recovery of cardiac function index (LVDP, ± LVdp / dtmax) was lower than that of the control group (P <0.05), LDH activity was significantly higher The corresponding control group (P <0.05), right ventricular weight was significantly higher than the control group rats (P <0.05). The results showed that appropriate IHH enhanced the development of rat heart resistance to ischemia / reperfusion injury; intermittent hypoxia is an important factor affecting its cardioprotection.