FIXATION OF RAT TAIL VERTEBRAE CAUSES MUSCLE FIBRE TYPE TRANSITION IN PARASPINAL MUSCLE

Summary StatementParaspinal musclecontain higher proportionof slow-twich fibers. The fixation of the rat tail induced transition of musclefiber typesin the paravertebral musclescharacterised by the decrease in the proportionof the slow typemyosin heavy chain.IntroductionLumbar degenerative kyphosisoften accompanies back pain, easy fatigability, fatty degeneration and atrophy of back muscles. There are two typesof skeletal musclefibers according to oxidative activities: slow-twich ( Type1) and fast-twitch ( Type2) fibers. Type2 fibers were subdivided into three types: Type2A, 2B and 2D/X. Each fiber typeprimarily expresses a specific isoform of myosin heavy chain (MHC). It has been known that back musclescontain higher proportionof MHC type1. However, the impact of kyphosison the proportionof fiber typesin the paravertebral muscleshas not been fully understood. The aim of this study is to analyze the transition of musclefiber typesafter kyophotic or straight fixation using a rat tail ...