The Change Of Skeletal Muscle Satellite Cells During Chronic Sciatic Nerve Compression In Rats Caused By A New Model

Objective To investigate the change of muscle satellite cells during the chronically compressed nerve injury induced by EC glue.Methods 30 random chosed SD rats weighing 60±10g were separated into two groups equally-- siatic nerve compression induced by EC glue and siatic nerve transaction. The right hind siactic nerve of 15 rats were subjected to the procedure of a new nerve compression model with EC glue, and the left siatic nerve were exposed only. The right siatic nerve of the other 15 rats were transected, and the left were exposed only. Electron microscope was used to evalue the thickness of myelin sheath, and RT-PCR, confocal microscope, Masson were used to determine the level of m RNA of muscle satellite cell for Pax7, Desmin and Myosin, and the degree of muscle atrophy and fibrosis.Results The muscle atrophy and fibrosis of nerve transaction showed up early after the nerve surgery, and deteriorated as time going. The thickness of myolin sheath at the time point of 4W in nerve compression group differed littlely with the control group, with low transcription level and quantity of muscle satellite cells. After 8 weeks, degeneration of thickness of myolin sheath get clearly, and muscle atrophy and fibrosis get worse, but did not reach the level of 4W of nerve transection even at 12 W.Conclusions EC glue model could simulate the process of clinical chronic nerve compression nicely. Muscle satellite cells proliferated during the early stage of nerve compression, but disabled differentiated failing to form normal myotubes which contribute to muscle repairmen.t.