Relation between microcurrent therapy and satellite cellsin the regeneration of induced skeletal muscle injuryin rat

BackgroundSevere injuries in skeletal muscle result in muscle weakness, which delays recoveryand contributes to progressive decline in muscle function. Microcurrent therapy isa novel treatment method used in soft-tissue injury and tissue regeneration therapy.The regenerative capacity of skeletal muscle tissue resides in satellite cells, thequiescent adult stem cells.AimThe present work aimed at investigating the possible relation between microcurrenttherapy and satellite cells in regeneration of induced skeletal muscle injury in albinorats.Materials and methodsTwenty-four male albino rats were divided into 2 groups: Control group andexperimental group (II): rats were subjected to gastrocnemius-soleus muscle injury(subgroup IIa), they were subdivided into subgroups IIa1 IIa2 sacrificed 1 and 3weeks after injury respectively. Subgroup IIb: Rats were subjected to muscle injury andmicro-current electric stimulator, was applied for 20 minutes for three sessions perweek. The animals were subdivided into subgroups IIb1 and IIb2 sacrificed 1 and 3weeks following the day of injury. Muscle sections were stained with hematoxylin andeosin, alpha smooth muscle actin (α-SMA) and CD34 immunostaining. Morphometricstudies and statistical analysis were performed.ResultsAtypical fibers were widely separated by connective tissue cells and revealed partialloss of striations in subgroup IIa. Some fibers recruited strong acidophilic sarcoplasmwith focal vacuolations in subgroup IIa1. In subgroup IIb1, some typical fibers, somecentrally located nuclei, and a few deeply acidophilic fibers were found. Striationswere found in some areas of the sarcoplasm. In subgroup IIb2 striations were foundin most areas of the sarcoplasm. A significant decrease in the mean area of atypicalfibers, a significant increase in the mean area% of α-smooth muscle actin-positivecells, and a significant increase in the mean area% of CD34-positive cells were foundin subgroup IIb compared with subgroup IIa.ConclusionA definite therapeutic effect of the microcurrent was found on induced skeletalmuscle injury, which was time dependent. This effect was proved to be related tosatellite cell activation.