力竭运动大鼠骨骼肌微损伤过程中Caveolin-3 mRNA表达变化

The Change of Caveolin-3 mRNA in the Course of Skeletal Micro-injury Induced by Acute Exhaustive Exercise

目的:观察大鼠力竭运动后不同时程Caveolin-3 mRNA的变化及其在运动损伤及修复中的作用。方法:48只成年雄性Wistar大鼠随机分为8组:安静对照组,运动后即刻、6 h、12 h、24 h、48 h、4 d、7 d组,每组6只。运动组进行一次性跑台力竭运动,采用HE染色观察骨骼肌形态学变化,测定血清NO、腓肠肌细胞膜Na+-K+-ATP酶、细胞内游离钙浓度,RT-PCR测定Caveolin-3 mRNA表达。结果:形态学结果(HE)显示,力竭运动后24 h、48 h时骨骼肌损伤最严重;在力竭运动后即刻和6 h时血清NO显著低于安静对照组(P<0.01),12h与对照组无显著差异,24 h、48 h时显著高于对照组(P<0.05,P<0.01),4 d和7 d时与对照组无差异;力竭运动后即刻细胞膜Na+-K+-ATP酶活性显著低于对照组(P<0.05),6 h、12 h、24 h显著低于对照组(P<0.01),48 h时虽有升高,但仍显著低于对照组(P<0.05),4 d和7 d恢复正常;在运动后即刻、6 h、12 h时细胞内游离钙浓度显著高于对照组(P<0.01),后虽下降,但24 h、48 h、4 d时仍显著高于对照组(P<0.05),7 d时与对照组无显著差异;力竭运动后6、12、24、48 h骨骼肌Caveolin-3 mRNA表达均显著高于对照组(P<0.01),4 d时仍显著高于对照组(P<0.05),7 d恢复正常。结论:一次性力竭运动造成细胞膜Na+-K+-ATP酶和细胞内游离钙代谢改变,Caveolin-3在骨骼肌微损伤过程中变化趋势为先升后降,可能与骨骼肌微损伤及损伤后的修复有关。

Objective This study was carried out to investigate the effect of caveolin-3 on the repairing skeletal muscle micro-injury induced by exhaustive downhill running.Methods Forty male Wistar rats were randomly and equally divided into following 8 groups：control group,and 0-hour,6-hour,12-hour,24-hour,48-hour,4-day and 7-day groups.The histology of skeletal muscle,serum NO,plasma membrane Na^＋-K^＋-ATPase activity,content of free calcium ion and caveolin-3 mRNA were observed after single bout of exhaustive downhill running.Results The most serious damage in skeletal muscle appeared 24 and 48 hours after the running;Serum NO content immediately and 6 hours after the running was significantly lower than in control group（P〈0.01）,and significantly higher 24 and 48 hours after the running than in control group（P〈0.05 and P〈0.01,respectively）,and no significantly differences were observed 12 hours,4 and 7 days after the running as compared with control group.The Na^＋-K^＋-ATPase activity was significantly lower immediately（P〈0.05）,6 hours,12 hours,24 hours（P〈0.01）and 48 hours（P〈0.05）after the running as compared to the control group,whereas there was no remarkable difference from the control group 4 days and 7 days after the running.The content of free calcium ion increased remarkably immediately and 6 hours,12 hours（P〈0.01）,24 hours,48 hours and 4 days（P〈0.05）as compared with the control group,and returned to its normal level 7 days after the running.Caveolin-3 mRNA was increased significantly immediately and 6 hours,12 hours,24 hours,48 hours（P〈0.01）,and 4 days（P〈0.05）after the running as compared with the control group,and returned to its normal level 7 days after the running.Conclusion Single bout of exhaustive downhill running could interrupt the metabolism of Na^＋-K^＋-ATPase and cytoplasm calcium ion.After the running,caveolin-3 mRNA increased firstly,then decreased following the development of skeletal muscle mocro-injury,suggesting that caveolin-3 participated in the injuring and repairing process of skeletal muscle.