摘要
目的:研究不同负荷负重跑训练对老龄大鼠骨骼肌内MG29蛋白(Mitsugumin29)表达的影响,探寻衰老性肌肉丢失(Sarcopenia)及其可训练性的机理。方法:32只17月龄的雄性Wistar大鼠被随机分为较大负荷运动组(HG)、中等负荷运动组(MG)和较小负荷运动组(LG)和对照组(CG),运动组各鼠分别负重其最大负荷的30%5、0%和60%进行跑台训练8周,每周6次,周日休息,每次跑2 min,间隔2 min为1组,共训练6组。每周称量所有大鼠体重,8周后取材,光镜下观测骨骼肌的一般形态,测定各鼠股直肌中段的匀浆脂褐质浓度、钙浓度,并采用Western Blot法测定股直肌中段的MG29蛋白的表达水平。结论:1)较小或中等强度的间歇负重跑运动对于延缓老龄大鼠骨骼肌的衰老来说是比较适宜的运动刺激,它能够有效提高骨骼肌内MG29蛋白的表达水平,从而使骨骼肌维持正常的兴奋收缩偶联结构,并促进胞外钙流入,从而保持或增强骨骼肌的正常收缩功能,相对降低细胞内的自由基水平,从而延缓了因衰老所致肌肉萎缩、丢失。2)较大强度的间歇负重跑运动是不适宜的运动刺激,该强度下运动使MG29蛋白水平减低,可能使骨骼肌的收缩功能减弱,且骨骼肌内的自由基水平显著升高,脂褐质大量蓄积。
Objective：To investigate the correlation between different load-bearing interval running and MG29 level in aged body of rats.Methods：32 Wistar rats aged at 17-months were chosen as the subjects of this experiment.They were grouped into 4 randomly.Of the 4 groups,one was control group（CG） and the other 3 were exercise training groups（EG）,which were respectively low load group（LG）,medium load group（MG） and high load group（HG） and were respectively burdened with 30%、50% and 60% the weights of their maximum loads.For the exercise training groups they were exerted interval run training on treadmill with the above burdens separately for 8 weeks.One set of training consisted of running 2 minutes and resting 2 minutes and 6 sets of this continuous training were exerted,one time for every day and 6 times for every week with Sunday resting.All the rats were weighed one time a week,their hair color and mental status were observed every day.At the end of the eighth training week and after the last training,the left mid-rectus femoris muscles of the subjects were cut up.Routine frozen sections were made with HE staining and afterwards an optical microscope was used to watch the histologic morphology determinations.After homogenation,in muscles the content of lipofuscin was assayed by fluorimetry colorimetry,the concentration of calcium was assayed by methylthymol blue colorimetry and MG29 level was assessed by western blot analysis.Conclusions：1）Low and medium intensity of interval load-bearing running may be a proper motor stimulation for delaying the aging process of skeletal muscles in rats.It can elevate the MG29 level in skeletal muscles effectively,consequently keep the normal structures of excitation contraction coupling,thus promote extracellular calcium entry,and hold even boost up the functions of skeletal muscles.As a result,the free radicals in fibers reduce relatively,muscular atrophy and lost decreases,and it happens that the process of sarcopenia delays.2）Maybe high intensity of interval load-bearing running is not a proper motor stimulation for aging skeletal muscle in rats,under this motor stimulation,the MG29 level falls significantly,thus the functions of skeletal muscles shrink greatly,and the free radical level rise apparently,the cumulation of lipofusion grows largely.
出处
《体育科学》
CSSCI
北大核心
2010年第9期73-81,共9页
China Sport Science
基金
河北省自然科学基金资助项目(C2008000177)
作者简介
李文惠（1973-），女，河北南宫人，在读硕士研究生，主要研究方向为运动保健、运动延缓骨骼肌衰老、运动伤病防治理论与实践，E-mail：liwenhui3061563@163．com
赵斌（1956-），男，河北张家口人，教授，博士研究生导师，主要研究方向为运动保健学、运动伤病防治的理论与实践、运动延缓骨骼肌衰老；
闫万军（1965-），男，山西祁县人，研究员，博士，硕士研究生导师，主要研究方向为运动促进健康的理论与应用。
