急性大、中强度运动对大鼠骨骼肌p38 MAPK、NF-kappaB活性,IL-6、MRFs mRNA的影响

Effect of Acute Exercise with High or Moderate Intensity on the p38 MAPK,NF-kappaB Activity,Interleukin-6,and MRFs mRNA in Skeletal Muscle of Rats

目的:探索急性大、中强度运动对大鼠肌肉发生相关因子p38 MAPK、NF-kappaB、IL-6、MRFs(MyoD、MyoG、Myf-5、MRF4)、MEF2c活性/mRNA影响。方法:66只雄性SD大鼠分为11组,C组(安静组)、大强度组H-0、1、6、16、24 h组(急性大强度运动后0、1、6、16、24 h组,跑台运动方案:1 h、27 m/min、倾角10%,运动30 min后休息5 min,同样强度再跑25 min),M-0、1、6、16、24 h组(急性中等强度运动后0、1、6、16、24 h组,运动方案:1 h、20 m/min、5%,运动30 min后休息5 min,同样强度再跑25 min)。检测各组大鼠腓肠肌p38、Phospho-p38、p65、Phospho-p65、IL-6 mRNA、MRFs(MyoD、MyoG、Myf-5、MRF4)mRNA、MEF2c mRNA水平。结果:(1)H-0、1、6 h组Phospho-p38、Phospho-p65、IL-6 mRNA显著高于C组(均P<0.01)。M-0、1、6 h组Phospho-p38及M-0、1h组Phospho-p65、IL-6 mRNA显著高于C组(均P<0.01),但均显著低于H对应组,其中M-0、1h组IL-6 mRNA显著性水平为P<0.05,其余为P<0.01。(2)H-0、1、6 h组MEF2c mRNA显著高于C组(均P<0.01),M-0、1 h组显著高于C组(均P<0.01)但显著低于H对应组(均P<0.05)。H-1、6 h组MRF4 mRNA,H-6h、M-6 h组MyoD mRNA,H-6、16 h组MyoG mRNA显著高于C组(均P<0.01)。M-6 h组MyoD mRNA显著低于H对应组(P<0.05)。(3)H-6 h、M-6 h组MyoD mRNA/MyoG mRNA比值显著高于C组(P<0.01),H-16 h组显著低于C组(P<0.01)。大、中强度运动后,该比值分别在24、16 h恢复至C组水平(P>0.05)。结论:(1)p38、NF-B活性、IL-6 mRNA均对运动刺激敏感,急性运动后,三者变化相似,特别是大强度条件下。p38活性、NF-B活性、IL-6 mRNA上调幅度及NF-B活性、IL-6 mRNA上调时间与运动强度有关。(2)MEF2c、MyoD mRNA均对运动刺激敏感。MEF2c、MyoD mRNA的上调幅度、MEF2c mRNA的上调时间与运动强度有关。MRF4、MyoG mRNA仅对大强度运动刺激敏感,Myf-5基因表达对运动刺激敏感。(3)大强度运动后,肌肉表型转化趋势经历了慢-快、快-慢两个阶段,后再恢复正常水平。中等强度运动后早期,表型转化同样为慢-快,表型转化结束较早。

Objective To explorer the effect of acute exercise with high or moderate intensity on the myogenesis-related factor p38 MAPK,NF-kappaB,Interleukin-6,MRFs（MyoD,MyoG,Myf-5,MRF4）,MEF2c activity or mRNA in skeletal muscle of rats.Methods Sixty six male SD rats were divided into three groups：control（C）,high intensity exercise（H）and moderate intensity exercise（M）.Running duration on the treadmill lasted for a total of 1 hour for both groups H and M.They underwent 30 minutes running with 5 minutes rest,and then continued another running for 25 minutes.Running at the speed of 27 m/min with 10% slope,and at the speed of 20 m/min with 5% slope was respectively arranged for groups H and M.Sampling of gastrocnemius was performed at 0 hour（H-0 and M-0）,1 hour（H-1 and M-1）,6 hours（H-6 and M-6）,16 hours（H-16 and M-16）,and 24 hours（H-24 and M-24）after exercise.The levels of phospho-p38,phospho-p38,phospho-p65,phospho-p65,IL-6 mRNA,MRFs（MyoD,MyoG,Myf-5,MRF4）mRNA,and MEF2c mRNA in gastrocnemiuses of rats were measured.Results（1）The phospho-p38,phospho-p65 and IL-6 mRNA at H-0,H-1,and H-6 were higher than in group C（P〈0.01）.The phospho-p38 at M-0,M-1,and M-6 and phospho-p65,IL-6 mRNA at M-0 and M-1 were higher than that in group C（P〈0.01）and lower than that in high intensity exercise groups（P〈0.05 to P〈0.01）.（2）MEF2c mRNA at H-0,H-1 and H-6,and at M-0 and M-1 was higher than in group C（P〈0.01）,but they were lower in moderate intensity exercise groups as compared with that in high intensity exercise groups（P〈0.05）.MRF4 mRNA at H-1 and H-6,and MyoD mRNA at H-6 and M-6 were higher than in group C（P〈0.01）.MyoD mRNA at M-6 was lower than in group H（P〈0.05）.（3）The ratio of MyoD mRNA/MyoG mRNA at H-6 and M-6 was higher than in group C（P〈0.01） and at H-1 and H-6 was lower than in group C（P〈0.01）.Normalization of the ratio was seen at 16 hours after both high or moderate intensity exercises（P〈0.05）.Conclusions（1）Exercise,especially high intensity exercise could irritate the activities of phospho-p38 and NF-ΚB,and IL-6mRNA.The magnitude of phospho-p38 and NF-кB activity,and the upregulation magnitude and duration of IL-6 mRNA was dependent on the intensity of exercise.（2）Both MEF2c and MyoD mRNA were sensitive to exercise,their upregulation magnitude was dependent on the intensity of exercise,as well as upregulation duration of MEF2c mRNA.MRF4 and MyoG mRNA were only sensitive to high intensity exercise,however,Myf-5 mRNA was desensitized to exercise.（3）Muscular phaenotype transformed from slow to fast and fast to slow after high intensity exercise,and finally returned to its normal level.The transformation of muscular phaenotype revealed the same tendency in the early phase after moderate intensity exercise,but returned to its normal level more rapidly.