Experimental Studies On The Different Expression Of Myosin Heavy Chain In Rabbit Semimembranosus' Sub-department

Objective:The currently study about skeletal muscle fiber types shows that each skeletal muscle fiber type's composition ratio is complex, the unity types are less. The previous studies on the rabbit semimembranosus's sub-department composition found that the composition and structure of muscle fiber's distribution are singler than other skeletal muscle. On the basis of that this study is to verify it by the experimental skeletal muscle morphological staining results, at the same time to detect the ratio of the muscle fibers myosin heavy chain (MHC) isoform at the molecular level and lay a foundation for further research of muscle fiber's structure, function and transformation mechanism by the gene expression microarrays chips.Methods:This experiment took 10 adult rabbits as the research object, either male or female, took their semimembranosus of right limbs. Verified its four sub-department two types of muscle fiber's distribution and the component ratio through the improvement of myosin ATPase staining method, at the same time used reverse transcription polymerase chain reaction (RT-PCR) to detect the mRNA composition and content of MHC I, MHC II a, MHC II b and MHC II x four isoforms.Results:For the four sub-department of rabbit semimembranosus, the inherent semimembranosus contained slow muscle (type I fiber) only, expressed MHC I type and a small amount of MHCⅡa gene. There was a small amount of slow muscle (type I fiber) at ventral Vice-semimembranosus and expressed a small amount of MHC I gene, others mainly contained fast muscle (type II fibers), expressed MHC II a, MHC II b and II x genes; while its dorsal and lateral only contained fast muscle, only expressed MHC II a, MHC II b and MHC II x genes.Conclusion:The results of the two experiments were consistent, the inherent semimembranosus was slow muscle, contained slow muscle fibers,that was type I fibers. The dorsal and lateral of Vice-semimembranosus was fast muscle and contained fast muscle fibers,that was type II fibers; in addition to a small amount of slow muscle fibers the ventral also mainly expressed fast muscle fibers.