运动诱导的大鼠腓肠肌细胞凋亡与肌纤维类型百分构成关系的研究  

The Correlation between Exercise-induced Apoptosis of Rats' Gastrocnemius and Their Muscle Fiber Type Percentage Compositions

作　　者：李江华[1] 邓树勋[1] 汤长发[2] 

机构地区：[1]华南师范大学体育科学学院,广州510006 [2]湖南师范大学体育学院,长沙410012

出　　处：《中国运动医学杂志》2008年第3期344-347,共4页Chinese Journal of Sports Medicine

摘　　要：目的:探讨运动诱导的骨骼肌细胞凋亡和肌纤维类型百分构成的关系。方法:30只成年雄性SD大鼠随机分为安静对照组(不运动)、中等强度运动组(18m/min,100min)和大强度运动组(28m/min,20min),每组10只。安静组和运动组大鼠分别于安静状态和运动后即刻处死,取后肢腓肠肌内侧头,分别以原位末端标记法(TUNEL)测试细胞凋亡,ATP酶染色法鉴定Ⅰ型和Ⅱ型骨骼肌纤维,SDS-PAGE凝胶电泳分离肌凝蛋白重链(MHC),MHCⅠ、MHCⅡa、MHCⅡb和MHCⅡx。结果:(1)安静对照组大鼠腓肠肌内侧头仅检测到少量TUNEL阳染细胞核;中等强度运动组有散在的TUNEL阳染细胞核,凋亡指数为19.01±6.61;大强度运动组也检测到TUNEL阳染细胞核,凋亡指数为11.51±4.33%。(2)中等强度运动组细胞凋亡指数与Ⅱ型肌纤维面积百分比的相关系数r为0.776(P<0.05);大强度运动组细胞凋亡指数与Ⅱ型肌纤维面积百分比的相关系数r为0.737(P<0.05)。(3)中等强度运动组细胞凋亡指数与MHCⅡa亚型百分比呈高度正相关(r=0.787,P<0.05);与MHCⅡb亚型百分比呈低度负相关(r=-0.334,P<0.05);大强度运动组的结果与中等强度组基本一致。结论:运动量是影响骨骼肌细胞凋亡率的关键因素之一,肌细胞凋亡率在一定程度上随运动量的增加而升高,并且Ⅱ型肌纤维(快肌纤维)百分比高的骨骼肌在大强度和中等强度跑台运动中更易发生细胞凋亡。Objective The relationship between exercise-induced apoptosis of rats＇ gastrocnemius and their muscle fiber type percentage compositions was studied. Methods 30 male adult Sprague-Dawley rats were random- ly divided into three groups ： control （C, n = 10）, moderate intensity exercise （PME, n = 10, treadmill training for 100min, 18m/min） and high intensity exercise （SHE, n = 10, treadmill training for 20min, 28m/min, ）. The rats were sacrificed immiadately after training and the gastrocnemius were separated for testing. The nuclei in apoptosis were labeled by TUNEL（terminal-deoxynucleotidyl transferase mediated dUTP nick end labeling）. The type Ⅰ muscle fibers and type Ⅱ muscle fibers were distinguished through ATPase coloration and the isoforms of MHC were separated into MHC Ⅰ , MHC Ⅱ a, MHC Ⅱ b and MHC Ⅱ x by SDA-PAGE electrophoresis. Results （1） Few TUNEL positive myonuclei were found in the control group. TUNEL positive myonuclei were found scattered in PME group and SHE group. The apoptosis index of PME group was 19.01 ± 6.61 ; the SHE group was 11.51±4.33%;（2）In PME group,the correlation coefficient of apoptosis index and the percentage of type Ⅱ muscle fibers was 0. 776 （P〈0. 05） ;in SHE group, the correlation coefficient of apoptosis index and the percentage of type Ⅱ muscle fibers was 0. 737（P〈0.05）;（3）In PME group,the apoptosis index showed a high positive correlation with the percentage of MHC Ⅱ a（r= 0. 787, P〈0.05）, and negative correlation with the percentage of MHC Ⅱ （r=- 0. 334, P〈0.05）. The results of SHE group were similar with the PME group. Conclusion The exercise volume was a key factor of muscle cell apoptosis, and the skeletal muscles with higher percentage of type Ⅱ muscle fibers were prone to induce apoptosis.

关 键 词：运动 骨骼肌 细胞凋亡 肌纤维类型 

分 类 号：R87[医药卫生—运动医学]