Morphofunctional characteristics of the thymus and muscle regenerates under laser irradiation and alloplasty of adult muscle tissue in the area of trauma

The effect of muscle tissue alloplasty and He-Ne laser radiation on the skeletal muscle regeneration and thymus function was studied. Allogenic muscle tissue was implanted from an adult rat. Without laser irradiation (series 1), initial enhancement of thymus recovery observed on day 7 after alloplasty (a characteristic stress response to operation) was followed by gradual destructive changes in the thymus tissue. On day 30 after alloplasty, connective tissue developed in the implantation area in muscle regenerates, and the muscle tissue accounted for 64 ± 2%. Implantation of unirradiated allografts into the muscles of recipient rats preirradiated with a He-Ne laser (series 2) resulted in a nearly complete destruction of the thymus and suppression of its function; the mitotic index of thymocytes was low. These changes were observed throughout the experiment starting immediately after the operation. In this case, the allogenic transplant retained the ability to develop: the 30-day repairing muscles consisted of 71 ± 2% of muscle tissue. When an allograft preirradiated with a He-Ne laser was implanted into unirradiated rats (series 3), thymus destruction at the beginning of the postoperative period was much less significant than in series 2 but more pronounced than in series 1. Then, thymus recovered more rapidly, the allogenic transplant was resorbed, and the muscle tissue in the regenerates accounted for 62 ± 3%.