聚氧化乙烯对急性后肢缺血大鼠运动耐力的影响及可能的作用机制

Effects of polyethylene oxide on exercise tolerance of acute ischemia hindlimb rats and its possible mechanisms

目的观察聚氧化乙烯(PEO)对急性后肢缺血大鼠运动耐力的影响,同时探讨其可能的作用机制。方法Wistar大鼠进行适应性跑步训练后建立大鼠双侧股动脉结扎模型,并经颈静脉留置输液导管;术后继续跑步训练并剔除静脉导管堵塞及不能学会跑步的大鼠,最后进入实验大鼠64只,随机分成2组,实验组(n=32)经颈静脉以7 ml/h的速度持续泵入PEO溶液10 min,对照组(n=32)以相同速度及时间持续泵入生理盐水,大鼠跑步至力竭,观察大鼠力竭运动时间,测全血乳酸(LD)、血清一氧化氮(NO)、超氧化物歧化酶(SOD)、乳酸脱氢酶(LDH)、肌酸激酶(CK)及腓肠肌的肌肉乳酸(LD)含量。结果实验组力竭运动时间为(774.72±171.49)s,较对照组的(687.56±166.08)s明显延长,差异有统计学意义(P=0.043);实验组大鼠NO和SOD含量为(4.25±1.75)μmol/L、(62.97±8.70)U/ml,分别较对照组的(3.51±1.06)μmol/L、(58.79±6.75)U/ml升高或者增强,差异均有统计学意义(P=0.047、P=0.036);与对照组比较,实验组大鼠肌肉LD含量明显降低[(2.79±0.10)lg mmol/g vs(2.95±0.11)lgmmol/g,P<0.01];两组血清CK、LDH活力、全血LD含量则差异无统计学意义(P>0.05)。结论 PEO可延长急性后肢缺血大鼠的力竭运动时间从而改善运动耐力,发挥抗疲劳作用。

Objective To evaluate the effects of polyethylene oxide （PEO） on the exercise tolerance of acute ischemia hindlimb rats, and to explore the possible mechanisms. Methods After adaptive running training of Wistar rats, bilateral femoral artery ligation models were established. Rats failing in running on treadmill, or with intravenous-catheter blocked were excluded. 64 rats were randomized into two groups. The rats in the experimental group （n=32） received an intravenous injection of PEO at the speed of 7 ml/h for 10 minutes. In the control group （n=32）, normal saline was infused under the same condition. After exhaustive exercise, the time of exhaustive exercise, the contents of blood lactic acid, serum nitric oxide （NO）, serum superoxide dismutase （SOD） activity, serum creatine kinase （CK） activity, serum lactate dehydrogenase （LDH） activity and lactic acid （muscle LD） of gastrocnemius muscle were determined. Results Compared with the controls, rats in the experimental group had a longer time of exhaustive exercise （P〈0.05）, increased NO content and SOD activity （P〈0.05）, and reduced LD content in gastrocnemius muscle（P〈0.01 ）. However, levels of CK, LDH activity and blood LD content were not significantly changed （P〉0.05）. Conclusion PEO can prolong the time of exhaustive exercise and improve the exercise tolerance in acute ischemia hindlimb rats.