Eccentric contractions of gastrocnemius muscle-induced nerve damage in rats.

Introduction We examined the effects of gastrocnemius eccentric contractions (ECs) on the sciatic nerve in rats. Methods: Rats were divided randomly into the following 3 groups: control, 180EC (ECs with 180°/s angular velocity), and 30EC (ECs with 30°/s angular velocity). Twenty ECs were induced by electrical stimulation of the gastrocnemius. On days 3, 7, and 10 after the ECs, nerve conduction velocity (NCV) was measured, and sciatic nerve branches were harvested for analysis. Results: A significant decrease in NCV was observed between the control and day-7 180EC. Significant reduction in the levels of myelin sheath protein zero (p0) between day 7 and day 3 180EC and a significant increase of macrophage-related protein and tyrosine kinase receptor C were observed between day 7 180EC and day 7 30EC. Conclusions: ECs with fast angular velocities induce functional and structural damage in innervating nerve. Muscle Nerve 50: 87-94, 2014 [ABSTRACT FROM AUTHOR]