Effect of Exercise Training on Histochemical Muscle Recovery after Sciatic Nerve Crush in Rat

Cho, Hyun Rae; Yoo, Ki Soo

Abstract

It is constant controversy that exercise influence muscle regeneration in peripheral neuropathy. The aim of this experiment is to show that treadmill running exercise under well-controlled conditions is to improve of regeneration in rat gastrocnemius muscles after sciatic nerve crushing injury. Male Sprague-Dawley rats (1 month old, weight 150~180 g) were submitted to bouts of exercise on a treadmill up a 10 degrees decline and speed is 20 m/min for 60 min per day and gastrocnemius muscles were analysed at different exercise periods (5, 10, 15, 20 and 40 days) by immunohistochemistry in comparison with injured non-exercised muscles. Rats were sacrificed at 12th (5 days exercise), 19th (10 days exercise), 26th (15 days exercise), 33rd day (20 days exercise), 61st day (40 days exercise) after sciatic nerve crushing injury. It showed that type II myofibers (target fibers) on center area had reinnervation at sciatic nerve crush injury at 26th day in exercise rats, as at 33rd day appeared giant type II myofibers, myofibers grouping observed in regenerative muscle character, component ratio of closed normal muscle showed at 61st day. Giant type II myofibers showed at 33rd day in non-exercise rats, however did not nearly normal muscle at 61st day. Therefore we concluded that treadmill running exercise is able to improve regeneration processes in gastrocnemius muscles after sciatic nerve crushing injury of rats.