Author/Editor		Snoj-Cvetko, E; Sketelj, J; Dolenc, I; Obreza, S; Janmot, C; d'Albis, A; Eržen, I
Title		Regenerated rat fast muscle transplanted to the slow muscle bed and innervated by the slow nerve, exhibits and identical myosin heavy chain repertoire to that of the slow muscle
Type		članek
Source		Histochem Cell Biol
Vol. and No.		Letnik 106, št. 5
Publication year		1996
Volume		str. 473-9
Language		eng
Abstract		The hypothesis that the limited adaptive range observed in fast rat muscles in regard to expression of the slow myosin is due to intrinsic properties of their myogenic stem cells was tested by examining myosin heavy chain (MHC) expression in regenerated rat extensor digitorum longus (EDL) and soleus (SOL) muscles. The muscles were injured by bupivacaine, transplanted to the SOL muscle bed and innervated by the SOL nerve. Three months later, muscle fibre types were determined. MHC expression in muscle fibres was demonstrated immunohistochemically and analysed by SDS-glycerol gel electrophoresis. Regenerated EDL transplants became very similar to the control SOL muscles and indistinguishable from the SOL transplants. Slow type 1 fibres predominated and the slow MHC-1 isoform was present in more than 90% of all muscle fibres. It contributed more than 80% of total MHC content in the EDL transplants. About 7% of fibres exhibited MHC-2a and about 7% of fibres coexpressed MHC-1 and MHC-2a. MHC-2x/d contributed about 5-10% of the whole MHCs in regenerated EDL and SOL transplants. The restricted adaptive range of adult rat EDL muscle in regard to the synthesis of MHC-1 is not rooted in muscle progenitor cells; it is probably due to an irreversible maturation-re-lated change switching off the gene for the slow MHC isoform.
Descriptors		MUSCLE, SKELETAL MUSCLE DENERVATION ADENOSINETRIPHOSPHATASE MYOSIN HEAVY CHAINS RATS HISTOCYTOCHEMISTRY IMMUNOHISTOCHEMISTRY IMMUNOENZYME TECHNIQUES ELECTROPHORESIS, POLYACRYLAMIDE GEL MUSCLE FIBERS, FAST-TWITCH MUSCLE FIBERS, SLOW-TWITCH