| This study aimed to explore the influence of different training modes on the subtypes changes in C57 mice's quadriceps muscle myosin heavy chain. Most of the previous studies suggest that exercise training can promote conversions between different subtypes of MHC, but the conclusions of previous studies are inconsistent. And the MHC isoforms changed accompanied the occurrence of aging. It is reported that there is a phenomena of reduction of MHC-â…¡b number and increase of MHC-â…¡x number in fast muscle of aged rats. In this study we trained three months old C57 mice for 28 weeks long by resistance, endurance and mixed exercise, then we observed changes of each subtype gene expression in mice quadriceps MHC under different training modes.Methods:32 three-month-old male C57BL/6 mices were randomly distributed into four groups:sedentary(C, n=8), endurance training(E, n=8), resistance exercise(R, n=8), mixing type training(M,n=8). After 28 weeks exercise intervening, quantitative Real-time PCR method is used to detect MHC-â… ,MHC-â…¡a,MHC-â…¡x,MHC-â…¡b mRNA expression in quadriceps muscles.Results:Compared with the quiet control group, the expression of four subtypes genes of MHC in resistance exercise group were increased significantly; Compared with quiet control group, the expression of MHCâ…¡gene in endurance exercise group were increased, but there is no significant influence on MHCâ… gene; Compared with quiet control group, the expression of four subtypes gene of MHC in mixed exercise group increased, and the MHCâ… ,â…¡a,â…¡x genes have significant differences, but MHCâ…¡b gene has no significant difference.Conclusions:(1) all of resistance exercise, endurance exercise and mixed exercise can significantly causes body weight loss of mice, suggested that there is a positive impact of exercise on weight loss;(2) resistance exercise makes the mRNA gene expression of all subtypes in C57 mice quadriceps muscle MHC increased significantly, and all of the influence have significant difference; (3) endurance exercise to C57 mice quadriceps endurance exercise MHC-â…¡type mRNA expression were significantly increased, whereas MHC-â… type mRNA gene expression was not obvious;(4) Mixed movement to C57 mice quadriceps MHC-â… , MHC-â…¡a, MHC-â…¡x mRNA expression increased significantly, on the MHC-â…¡b mRNA gene expression was not obvious. |
