The Fiber Type Transition Between Two Types Skeletal Muscle Cells Cultured In Vitro

Objective: To investigate the phenomenon and features of transformation between fast and slow muscle fiber, we tested MHC isoforms expression of them cultured in vitro in different glucose concentration.Methods: 1. Identify the muscle fiber type of the seminembranous compartment(Fast type muscle,â…¡)and the innherent semimembranosus compartement(Slow type muscle,â… ) of rabbit by ATPase stain method. 2. Seminembranous compartment and innheren semimembranosus compartement of rabbit were obtained and divided in four groups:(1)Tissue group; Obtained two muscle compartment tissues respectively;(2)Trypsin digestion group; two types muscle fiber obtained by trypsin disposing;(3)High glucose cultured group:Cultured two types muscle fiber in vivo with high glucose; Collecting cells after cultured cells at 1, 3, 7days.(4)Low glucose cultured group: Cultured two types muscle fiber in vivo with low glucose; Collecting cells after cultured cells at 1, 3, 7days. MHC isoforms of two types muscle fiber in four groups were tested by RT-PCR.Results: 1) Inherent semimembranosus compartment displayed the lighter colors while semimembranous dorsle compartment displayed the deeper colors by ATPase co-culture method.2) Tissue group: The cells of inherent semimembranosus compartment expressed MHCâ… and did not erpressed MHCâ…¡a, â…¡b and â…¡x. While the cells of semimembranous dorsle compartment expressed MHCâ…¡a, â…¡b and â…¡x and did not express MHCâ… .3) Trypsin digestion group: The cells of inherent semimembranosus compartment expressed MHCâ… and did not erpress MHCâ…¡a, â…¡b and â…¡x. While the cells of semimembranous dorsle compartment express MHCâ…¡a, â…¡b and â…¡x and did not express MHCâ… .4) High glucose cultured group: The type â… muscle fiber cultured with high glucose expressed mainly MHC â… and merely â…¡a, â…¡b, â…¡x at day 1. The erpression level of MHCâ… decreased significantlier at day3, the erpression level of MHCâ…¡a,MHCâ…¡b and MHCâ…¡x increased significantlier than that at day1. The erpression level of MHCâ… decreased significantly at day7 While the erpression level of MHCâ…¡a, MHCâ…¡b and MHCâ…¡x expression did not change.Type â…¡muscle fiber culture expressed MHCâ…¡a, MHCâ…¡b, MHCâ…¡x and not MHCâ… at day 1. The erpression level of MHCâ…¡a, MHCâ…¡b, MHCâ…¡x and MHCâ… at day3 and 7 had not differences compared top that at day 1.5) Low glucose cultured group: The typeâ… muscle fiber cultured expressed mainly MHCâ… and merely MHCâ…¡a, MHCâ…¡b and MHCâ…¡x at day1. The erpression level of MHC â… was also expressed at day3 and expression the level had not differences significantlier compared to that at day1. While the erpression level of MHCâ…¡a, MHCâ…¡b, MHCâ…¡x increased significantlier than that at day1. The erpression level of MHC â…  at day7 had not differences significantlier compared to that at day3. The erpression level of MHCâ…¡a, MHCâ…¡b, MHCâ…¡x had not differences significantlier compared to that at day3.Typeâ…¡ muscle fiber cultured with low glucose expressed MHCâ…¡a, MHCâ…¡b, MHCâ…¡x and did not express MHCâ… at day1. At day3 they also expressed MHCâ…¡a, MHCâ…¡b and MHCâ…¡x the incresing level of MHCâ…¡b and the decreasing MHCâ…¡x. Was all differences significantlier compared to that at day1, while MHC â… was going to expressing. The expression level of MHCâ…¡a, MHCâ…¡b, MHCâ…¡x at day7 was similar to that at day3 but had not differences significantly, the level of MHCâ… expression was increased significantlier than that at day3.Conclusion: Two types of muscle fiber had not counterchange each other during isolating procedure. Type â… muscle fiber was going to transform towards type â…¡either cultured with high glucose in vitro at day1 low glucose.