缺氧预处理对模拟失重大鼠比目鱼肌萎缩的预防

目的了解缺氧预处理对失重状态下发生的骨骼肌萎缩是否有预防作用。方法采用大鼠尾部悬吊法建立模拟失重动物模型，将雌性SD大鼠按体重配对原则随机分为对照组（CON）、尾部悬吊组（SUS）及缺氧预处理＋尾部悬吊（HCP＋SUS）组。首先，对HCP＋SUS组进行1周的缺氧预处理。处理完成后，将SUS及HCP＋SUS组大鼠尾部悬吊2周。试验结束处死3组大鼠，取双后肢比目鱼肌，分别称重。将部分比目鱼肌制成匀浆，取上清液用于超氧化物歧化酶（SOD）、丙二醛（MDA）的检测。结果尾部悬吊2周后，SUS组大鼠双后肢比目鱼肌湿重明显低于CON及HCP＋SUS组（P〈0．01）。与SUS组相比，HCP＋SUS组比目鱼肌SOD活性明显升高（P〈0．05），MDA水平明显降低（P〈0．05）。结论缺氧预处理可提高大鼠骨骼肌的抗氧化能力，对失重状态下发生的骨骼肌萎缩有预防作用。

Preventive Effects of Hypoxic Preconditioning on Rat Soleus Muscle Atrophy Induced by Simulated Weightlessness

Objective To find out whether hypoxic preconditioning(HCP) had a preventive effect on skeletal muscle atrophy occurring in simulated weightlessness.Method A rat tail-suspension model was established consisting of 60 female SD rats which,according to pairing by body weight,were randomly divided into 3 groups of control(CON),tail-suspension(SUS),and hypoxic preconditioning plus tail-suspension(HCP SUS).The rats of the HCP SUS group were pretreated for one week,with 5 cycles of 30 min 10% O_2 provided for the rats at intervals of 5 min daily.Thereafter,the rats of the SUS and HCP SUS groups were hindlimb unweighted for two weeks.All the 3 groups of rats were executed and the soleus muscles of their hindlimbs were dissected and weighed respectively post-suspension.Part of the soleus muscles were then made into homogenate for detecting activities of the superoxide dismutase(SOD) and contents of the malondialdehyde(MDA).Result It had been found that,after two-week tail-suspension,wet weights of hindlimb soleus of the rats in SUS group decreased obviously as compared with those of the rats of the CON and HCP SUS groups(P<0.01),and that,as compared with the SUS group,soleus SOD activity and MDA content of the rats of the HCP SUS group evidently increased(P<0.05) and evidently decreased(P<0.05) respectively.Conclusion Hypoxic preconditioning may improve enzymatic antioxidant activity of rat skeletal muscles in simulated weightlessness and partially prevent rat soleus muscle atrophy induced by simulated weightlessness.