摘要
目的通过大鼠尾部悬吊成功造废用性骨骼肌萎缩模型,将氯沙坦灌胃干预,以大鼠空腹血糖、胰岛素、胰岛素抵抗指数、比目鱼肌Glut-4等为观测指标,探讨胰岛素抵抗在废用性骨骼肌萎缩发生过程中的作用和氯沙坦对其改善效果及机制。方法选用健康活泼雌性SD大鼠24只,适应性饲养3 d后按体质量随机配对原则随机分为4组（分别是C、CD、TS、TD组,n=6）。TS、TD组大鼠单笼饲养,尾部悬吊,前肢着地,后肢悬空,C、CD两组大鼠分组用标准鼠笼群养,每笼3只。CD、TD两组灌服氯沙坦溶液10 mg/kg/d（每100 g体质量的给予1 mg氯沙坦灌胃）,给其他2组大鼠灌服蒸馏水2~3 m L/d。动物实验进行2周后取出两侧比目鱼肌。空腹血糖采用葡萄糖氧化酶法测定,空腹胰岛素采用放射免疫法,平行管测试。结果 （1）尾部悬吊2周导致大鼠的体质量、比目鱼肌的质量、比体质量明显下降（P〈0.05）;（2）与C组比较,TS组的空腹血糖、胰岛素抵抗指数明显升高（P〈0.01）,TD组的空腹血糖明显升高（P〈0.05）,胰岛素抵抗指数无显著性差异（P〉0.05））;（3）TS组的比目鱼肌Glut-4蛋白与其他3组相比明显下降（P〈0.05）,TD组与C组无显著性差异。结论两周尾部悬吊可引起大鼠比目鱼肌的发生严重的废用性萎缩。废用性骨骼肌萎缩时出现严重的胰岛素抵抗现象,胰岛素抵抗指数升高。比目鱼肌Glut-4蛋白含量和功能显著降低,是胰岛素抵抗发生的一个重要因素。氯沙坦可以明显减轻胰岛素抵抗现象,对于废用性骨骼肌萎缩有一定的预防作用。
Objective The purpose of this research was to investigate the relationship between the muscle atrophy and the insulin resistance induced by the tail- suspension,and the prevention effects of losartan on these indexes were discussed.Methods 24 SD female rats were the subjects. All animals were provided with standard rodent food and water and housed in an environment- controlled room. Following 3 days of acclimation,rats were assigned to four groups randomly（ C、CD、TS、TD group; n = 6）. Every rat of tail- suspension was housed in a single cage,and the other two groups were separatively fed in the common cages. Rats of CD and TD groups were given Losartan 1 mg /100 g body mass everyday,the other rats with the same volume of water each time. All procedures for this experiment were approved by the Animal Care and Use Committee of Beijing Sport University. Soleus were got at the end of 2 weeks period. Fasting blood glucose and fasting insulin were tested and the intracellular protein Glut- 4 were determined by Western Blot. Results（ 1） Compared with control group rats,soleus wet weight / body mass of TS group decreased by 50. 0%,P 〈 0. 01,the relative weight of TD group was remarkably smaller than C or CD ones,while it was bigger than TS’,P 〈 0. 05.（ 2） Insulin resistance acompied with muscle atrophy induced by tail- suspension. Glut- 4 in soleus of TS became less than C’s,while CD’s was more than C’s,P 〈 0. 05.（ 3） Among the four groups,only TS group’s Insulin resistance index was much higher than control group,P 〈 0. 05. Conclusions Two weeks tail- suspension led to severe soleus atrophy in rats. Soleus wet weight and relative weight ratio proved the facts. Disuse muscle atrophy acompied with severe insulin resistance,which implied that Glut- 4 played a roll during the course of atrophy. Losartan displayed some prevention effects on the procedure and the the mechanism need to be further studied.
出处
《西安体育学院学报》
CSSCI
北大核心
2015年第1期89-93,共5页
Journal of Xi'an Physical Education University
基金
高等学校博士学科点专项科研基金项目(20070043008)
