Restoration of skeletal muscle contusions by the transplantation of skeletal muscle satellite cells

Abstract

Objective To probe the transplantation of skeletal muscle satellite cells of new-born rats for repairing skeletal muscle contusions. Methods Thirty-six Sprague-Dawley adult rats were separated at random into experimental and control groups (including a normal saline control group and a normal control group). Contusions were created on the left hind legs of rats in the experimental group. The cells were cultured and antibodies were identified through immunocytochemical staining and fluorescence labeling. In the experimental group, 0.2 ml of a muscle satellite cell suspension was slowly injected into the medial and lateral heads of the right calf gastrocnemius. The normal saline control group was injected with an equal volume of normal saline solution at the same sites. On the 5th, 10th and 15th day after the operation, EMG wave-amplitude and wave-width were recorded. The recovery rate of the muscle's wet weight and the gray value of a muscle fiber transverse section were determined.Two-factors analysis of variance was performed on the data. Results Before transplantation the muscle satellite cells were bright red after staining and their nuclei were blue after fluorescence labeling. After the operation the number of cells fluorescing and the strength of the fluorescence gradually decreased. The transplanted cells formed myotubes, melted into the muscle tissue and gradually took part in the restoration. The stained muscle satellite cell nuclei were free in intercellular space and melted into the basement membrane gradually. The outlines of the muscle tissue became progressively clearer. EMGs showed the fibrillation potentials as well as positive sharp waves reduced, but they too tended to become similar to those from the normal side. Restoration of EMG wave-amplitude and wave-width in the experimental group was better than in the saline control group and close to those in the normalcontrol group. The gray value of the muscle fiber transverse section area under HE staining was significantly lower at the 5th day post transplantation in both the experimental group and the saline control group than in the normal control group. At the 10th and 15th days post transplantation, the average gray value in the experimental group had increased significantly more than in the saline control group, and it was close to the normal control group average. In the experimental group the recovery rate of muscle wet weight was close to 1, but in the saline control group it was less than 1. Conclusions Transplanting skeletal muscle satellite cells of new-born rats can produce evident effects in renovating injured muscles. Key words: New-born rats; Muscle satellite cells; Transplantation; Contusions