缺血后处理改善微循环、减轻骨骼肌缺血再灌注损伤的实验研究

目的:观察缺血后处理(I-postC)对大鼠后肢骨骼肌微循环和缺血再灌注(I/R)损伤的影响。方法:健康雄性Wistar大鼠24只,随机分为3个实验组,即I/R组、I-postC组和预处理(IPC)组(n均=8),左后肢作为自身对照。无创动脉夹夹闭右侧股动脉4h,松夹再灌注2h建立大鼠后肢I/R模型。于再灌注结束时分别检测大鼠胫前肌血氧饱和度(StO2)、微循环、血流动力学变化以及骨骼肌湿、干重比值(W/D)和骨骼肌组织丙二醛(MDA)含量。结果:(1)再灌注I-postC减轻I/R对心功能的抑制,I-postC组+dp/dtmax和-dp/dtmax较I/R组分别增高18.5%和21.3%(P<0.05),I-postC组W/D较I/R组降低4.9%(P<0.05);I-postC组MDA较I/R组降低40.9%(P<0.05)。(2)再灌注I-postC组实验侧细静脉血流速度较I/R组增加8.3%(P<0.05),细动、静脉收缩减轻(细动、静脉内径较I/R组分别增加14.8%和29.1%,P<0.05),与IPC的保护效果接近(P>0.05)。结论:I-postC显著减轻骨骼肌I/R损伤,其保护机制与改善微循环有关。

Ischemic Postconditioning Protects Skeletal Muscle from Ischemic Reperfusion Injury through Improving Microcirculation in Rat Hind Limbs

Objective: To investigate the effects of ischemic postconditioning (I-postC) on skeletal muscle microcirculation and ischemia/reperfusion (I/R) injury in rat hind limbs. Method: Twenty four male Wistar rats were randomly divided into I/R, I-postC and ischemic preconditioning (IPC) groups (n=8). Hind limb ischemia/reperfusion was induced by clamping right femoral artery. Left hind limb was used for self control. The oxygen saturation of hemoglobin (StO2), microcirculation, hemodynamics, wet/dry ratio (W/D) and the content of malondialdehyde (MDA) were detected at 2h after reperfusion. Results: (1) Compared with I/R group, dp/dtmax and-dp/dtmax in I-postC group increased 18.5% and 21.3%, respectively (P<0.05), and W/D in I-postC group decreased 4.9% (P<0.05) at 2h after reperfusion. MDA decreased by 18.3% in I-postC group (P<0.05) compared with that of I/R group. (2) It was also found that 2 h after reperfusion, blood velocity in venule increased by 8.3% in I-postC group compared with that in I/R group(P<0.05), and internal diameter of arteriole and venule increased by 14.8% and 29.1% compared with those in I/R group, respectively (P<0.05). There was no significant difference between I-postC and IPC groups (P>0.05). Conclusion: I-postC can protect the skeletal muscle ngainst reperfusion injury through improving microcirculation.