运动训练对糖尿病大鼠骨骼肌神经营养因子-3水平的影响

The effects of swimming on neurotrophin-3 levels in the skeletal muscles of diabetic rats

目的 探讨运动训练对糖尿病大鼠骨骼肌神经营养因子-3（NT-3）水平的影响.方法 选取12周龄健康雄性SD大鼠39只,分成糖尿病组27只和正常血糖组12只.糖尿病组建立糖尿病模型采用链脲霉素（STZ,55 mg/kg体重）注射诱导,27只大鼠中有21只造模成功.根据2组运动的情况,将糖尿病组造模成功的21只大鼠再分成糖尿病运动8周组、糖尿病运动4周组和精尿病对照组,每组7只;正常血糖组12只再分成正常运动8周组和正常对照组,每组6只.糖尿病运动8周组、糖尿病运动4周组和正常运动8周组的大鼠均进行相应时长的游泳训练,每日游泳训练60 min,每周训练5 d.糖尿病对照组和正常对照组不参加游泳训练.5组大鼠均于正常运动8周组最后1次训练后24 h内取标本,运用酶联免疫吸附测定法（ELISA）测定大鼠股四头肌内NT-3.5组大鼠均于人组1,4,8周后采用肌电图诱发电位仪测定大鼠尾神经传导速度（CNCV）.结果 糖尿病对照组大鼠股四头肌NT-3显著低于糖尿病运动8周组、正常运动8周组和正常对照组组（P〈0.05）,但与糖尿病运动4周组比较差异无统计学意义（P〉0.05）.大鼠骨骼肌NT-3水平与CNCV呈显著正相关（r=0.405,n=28,P〈0.05）.结论 运动训练引起的骨骼肌中NT-3水平升高可能是糖尿病神经病变改善的因素之一.

Objective To explore the effects of exercise on the levels of neurotrophin-3 （ NT-3 ） in the skeletal muscles of streptozotocin-induced diabetic rats. Methods The rats were divided into an 8-week exercise group （A）, a4-week exercise group （B）, a diabetes control group （C）, an exercise group （D） in which no dia- betes was induced, and a control group （ E）. The rat model of diabetes was induced in the rats of groups A, B and C by intra-abdominal injection of streptozotocin （STZ） at 55 mg/kg. The exercising rats were forced to swim for 60 minutes once daily, 5 days a week. The levels of NT-3 in skeletal muscles were measured with an enzyme-linked immunosorbent assay. Cadual nerve conduction velocity （CNCV） in all of the rats was evaluated at the beginning, and after 4 and 8 weeks of swimming exercise. Results NT-3 levels in the skeletal muscles in group C were sig- nificantly lower than in groups A, D and E. There was no statistically significant difference in NT-3 levels between groups B and C. The NT-3 levels showed a significant positive correlation with CNCV at the 8tb week. Conclusions The increase in NT-3 levels of skeletal muscles induced by exercise could contribute partially to the im- provement of diabetic neuropathy.