中等强度训练干预大鼠骨骼肌抗增殖蛋白PHB1表达及线粒体呼吸功能的变化

背景:研究显示长期中等强度规律运动可以改善骨骼肌细胞线粒体电子呼吸链复合体酶的活性,从而提高其做功能力和抵抗疲劳能力。目的:探讨中等强度训练对大鼠骨骼肌内抗增殖蛋白及线粒体呼吸功能的影响。方法:32只健康雄性SD大鼠随机分为2组:安静对照组、中等强度训练组,每组16只。中等强度训练组的训练方案:第1周以10 m/min速度跑,每周6 d,每天10 min,坡度10°;第2周以15 m/min速度跑,每周6 d,每天增加10 min至60 min结束,坡度10°;第3-8周以15 m/min速度跑,每周6 d,每天60 min,坡度10°。末次实验后48 h处死大鼠,提取骨骼肌以及线粒体,检测线粒体呼吸控制率、ATP含量、活性氧水平、复合体V活性及PHB1蛋白表达。结果与结论:①与安静对照组相比,中等强度训练组骨骼肌线粒体呼吸控制率显著性升高(P<0.001)、ATP含量显著性升高(P<0.05)、活性氧水平显著降低(P<0.001)、复合体V活性显著升高(P<0.05)、PHB1表达显著升高(P<0.01);②通过相关性分析得出:经过8周中等强度训练后大鼠骨骼肌内PHB1的表达分别与ATP含量、复合体V活性呈正相关,与活性氧水平呈负相关;③结果表明,中等强度训练通过促进PHB1表达提高线粒体氧化磷酸化功能,维持线粒体膜结构,增强线粒体呼吸功能。

Changes of mitochondrial respiratory function and PHB1 expression in rat skeletal muscle after moderate-intensity training

BACKGROUND: Studies have shown that long-term moderate-intensity regular exercise can improve the activity of mitochondrial respiratory chain complex enzymes in skeletal muscle cells, thereby improving their power capability as well as the ability to resist fatigue. OBJECTIVE: To explore the effect of moderate-intensity training on prohibitin (PHB) expression and mitochondrial respiratory function in rat skeletal muscle. METHODS: Thirty-two healthy male Sprague-Dawley rats were randomly divided into two groups: quiet control group and moderate-intensity training group, each of 16 rats. In the moderate-intensity training group, the treadmill training was performed at a slope of 10°: in the 1 st week, running at 10 m/min, 10 minutes per day, 6 days per week;in the 2 nd week, running at 15 m/min, increased from 10 minutes per day to 60 minutes per day with an increase of 10 minute per day, 6 days per week;in the 3 rd to 8th week, running at 15 m/min, 60 minutes per day, 6 days per week for a total of 8 weeks. Rats were sacrificed at 48 hours after the final experiment, and mitochondria were extracted from skeletal muscle samples. Mitochondrial respiration control rate, adenosine triphosphate content, reactive oxygen species level, complex V activity and PHB1 protein expression were measured. RESULTS AND CONCLUSION: Compared with the quiet control group, in the moderate-intensity training group, mitochondrial respiration control rate in the skeletal muscle increased significantly (P < 0.001), adenosine triphosphate content increased significantly (P < 0.05), reactive oxygen species level decreased significantly (P < 0.001), the activity of complex V was significantly increased (P < 0.05) and PHB1 expression was significantly increased (P < 0.01). The correlation analysis showed that after 8 weeks of moderate-intensity training, the expression of PHB1 in the skeletal muscle of rats was positively correlated with adenosine triphosphate content and complex V activity, and negatively correlated with reactive oxygen species level. Therefore, moderate-intensity training improves mitochondrial oxidative phosphorylation, effectively maintains mitochondrial membrane structure and enhances mitochondrial respiratory function by increasing the expression of PHB1.