Quantitative changes of schwann and mast cells in the process of peripheral nerve regeneration.

One of the most common problems in the fields of orthopedic surgery and neurology is that of the injured peripheral nerve. Injured nerve fibers in the adult mammalian peripheral nervous system can and often do regenerate, thereby restoring at least some lost faunctions. During the past decade enormous progress has been made in the understanding of the cellular events and molecular changes during degeneration and regeneration of peripheral nerves. However, our knowledge of the regulatory mechanisms and signaling cascades underlying the complex molecular regeneration program is still very limited despite an enormous amount of new experimental data. Injure to peripheral nerve initiates a complex cascade of signals involving neurons, glia and cells of the immune system. The question of which cells are responsible for nerve survival and tissue repair mechanisms after injury remains controversial. Although it has largely been demonstrated that macrophages and Schwann cells play important roles in degrading and removing myelin few data have been reported regarding mast cells in Wallerian degeneration. The present study has been designed to evaluate the correlation between Schwann and mast cells during regeneration of the injured peripheral nerve. Animals were divided into two groups: experimental and intact rats. The left sciatic nerve was separated from the surrounding tissue, was transected in its mid-thigh portion and sewed up. Sewed sciatic nerves were obtained and used for morphological and Immunocytochemical observation 2 and 12 day, and 1 month after transection. Our experimental data reveals that the mast cells, as well as Schwann cells, play a pivotal role in regeneration process after injury. The correlation between the changes of quantity of schwann cells and mast cells during the regeneration of injured peripheral nerve was not revealed.