Promotion of Nerve Regeneration in Peripheral Nerve by Short-Course FK506 after End-to-Side Neurorrhaphy

Abstract

To discuss the feasibility of peripheral nerve injury treated by end-to-side neurorrhaphy in clinic and to evaluate the effect of short-course FK506 on promoting nerve regeneration after end-to-side neurorrhaphy. Thirty adult male Sprague Dawley rats were randomly divided into 3 groups: Group A, 10 rats received end-to-end anastomosis; Group B, 10 rats received end-to-side neurorrhaphy; Group C, 10 rats received the same operation as Group B. After operation, rats in Groups B and C received muscle injection with saline water (1 mg/kg x d(-1)) and FK506 (1 mg/kg x d(-1)), respectively, both for 4 wk. Histological and morphological examinations were performed 12 wk after the operation. In the 2nd, 4th, 6th, 8th, and 12th wk after operation, function recovery analysis was performed. The results of histological and immunochemistry study (the total number of Schwann cells and the axon numbers at the distal stump of the peroneal nerve, wet weight of extensor digitorum longus muscle) suggested that there were significant differences between Group B (saline water group) and Group C (FK506 group) (P < 0.05), also between Group A (end-to-end group) and Group C (P < 0.05). There were statistically significant differences in function recovery (peroneal functional index and sciatic functional index) between Groups B and C (P < 0.05) and also between Groups A and C (P < 0.05). End-to-side repair combined with FK506 has a potential for application in selected cases of peripheral nerve injury in clinic.