运动结合补充亮氨酸通过抑制炎性反应促进C26荷瘤小鼠骨骼肌蛋白质沉积研究

Exercise in Combination With Leucine Supplementation Promoting Skeletal Muscle Protein Deposition in C26 Tumor Bearing Mice via Inhibiting Inflammatory Response

探讨运动结合膳食补充亮氨酸对癌性恶病质骨骼肌蛋白质沉积的影响及机制。方法:4周龄雄性BALB/c小鼠24只,根据体重随机分为正常对照组(C组)、荷瘤组(T组)及运动结合补充亮氨酸干预组(TEL组),其中T组与TEL组小鼠进行荷瘤处理。C组与T组小鼠进食添加3.4%比例丙氨酸饲料,TEL组饲料中则添加5%比例亮氨酸,实验期每日称量计算采食量。TEL组小鼠每周一、三、五进行无负重游泳运动30 min,二、四、六进行10组抗阻运动(每组30 s,组间间歇1 min),末次运动间隔24 h后(含禁食8 h)称重并处死全部小鼠,分离腓肠肌称重并制备血清。计算小鼠累积采食量与体重变化;酶联免疫吸附(ELISA)法检测血清与腓肠肌肿瘤坏死因子(TNF)-α与白介素(IL)-6含量;Bradford法进行蛋白定量;抓握力计测量小鼠肌力。结果:与C组小鼠相比,荷瘤导致小鼠累积采食量呈下降趋势,体重、腓肠肌湿重、腓肠肌蛋白总量、肌原纤维蛋白含量、肌浆蛋白含量与肌力均显著下降(P<0.01),而血清与腓肠肌TNF-α、IL-6含量则显著增加(P<0.01)。TEL组小鼠与C组相比也表现出了相同的变化趋势,但较T组小鼠具有显著改善(P<0.05或P<0.01)。结论:运动联合5%膳食亮氨酸干预可显著增加C26荷瘤小鼠骨骼肌蛋白质沉积,其机制可能与其对炎性反应的抑制有关。

Objective:To investigate the effect of concurrent exercise training in combination with leucine supplementation on skeletal muscular protein deposition and preliminarily analyzes the possible mechanism.Methods:24 four-week-old male BALB/c mice were randomly divided into normal control(C),tumor bearing(T)and tumor bearing received exercise and leucine supplementation group(TEL)by body weight,mice in T and TEL group will then suffered tumor inoculation.Mice in normal control(C)and tumor bearing(T)group were treated with normal chow diet supplemented with 3.4%alanine,while mice received exercise and leucine supplementation(TEL)were fed with formulated diet contained 5%leucine.And,food intake was calculated daily.TEL mice received 30 minutes swimming training 3 days per week(Monday,Wednesday and Friday)without external load,and 3 days(Tuesday,Thursday and Saturday)resistance exercise training(10 sets per day,30 seconds per set with 1 minute interval between sets).All mice were weighed and sacrificed 24 hours post the final training bout with 8 hours fasting period,after which the gastrocnemius muscle were separated and weighed,and the serum were also prepared.Both cumulative food intake and body weight change were calculated.The content of TNF-αand IL-6 in gastrocnemius muscle and serum were determined by ELISA.The protein content was analyzed using commercial bradford kit.The maximal grip strength was measured with a commercial grip strength meter.Results:Compared with mice in Group C,the results showed that tumor bearing induced downward trend in cumulative food intake,body weight,wet gastrocnemius muscle weight,total protein content,sarcoplasmic protein content,myofibrillar protein content and muscle strength decreased significantly(P<0.01),while both TNF-αand IL-6 content in serum and gastrocnemius were obviously increased(P<0.01).Mice in TEL group showed the same pattern of change when comparing with C group,but were also were found be ameliorated by treatment of exercise in combination with leucine supplementation when comparing with mice in T group(P<0.05 or P<0.01).Conclusion:Exercise training combined with 5%leucine supplementation significantly ameliorates skeletal muscular protein deposition in C26 tumor bearing mice,which may be correlated with inhibiting the inflammatory response.