The expression of myosin heavy chain isoforms of human normal laryngeal muscles and the difference between the adductor and abductor / 临床耳鼻咽喉头颈外科杂志

ABSTRACT

OBJECTIVE@#To investigate the expression of myosin heavy chain (MHC) in normal laryngeal muscle and the difference between the adductor and abductor.@*METHOD@#Seven patients with total laryngectomy were enrolled in this study. The adductor muscles were acquired from the lateral cricoarytenoid (LCA) muscle and the abductor muscles were acquired from the posterior cricoarytenoid (PCA) muscle. The expression of myosin heavy chain were detected with fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining respectively.@*RESULT@#(1) MHC-II b was expressed in laryngeal muscles at mRNA levels, and not expressed at the protein level; (2) At both mRNA level and protein level, the expression of MHC-I was higher in the PCA muscles than in the LCA muscles while MHC-II level was higher in the LCA muscles than in the PCA muscles.@*CONCLUSION@#(1) MHC-II b protein was not expressed in human laryngeal muscles; (2) Phenotypic differences were significant in laryngeal adductor and abductor muscles based on their different functions. PCA contained larger percentage of MHC-I fibers, while LCA contained more MHC-II fibers.