Autotomy prevention by amitriptyline after peripheral nerve section in different strains of mice.

This study evaluates the degree of autotomy induced by anesthesia dolorosa after transection of the sciatic and saphenous nerves in four different strains of mice, and the effectiveness of amitriptyline administration in two of them. The self-mutilating lesions were assessed by means of an autotomy score for one month after denervation. The onset of lesions generally occurred during the first week, starting in the nails and progressing proximally. Autotomy behavior developed differently in the mouse strains studied, involving 88% of the paw areas in OF1 mice, 61% in Balb-C, 35% in NMRI, and 15% in B6CBAF1. Two selected strains, OF1 and NMRI, were treated with amitriptyline (8 mg/kg/day, p.o.) from different intervals pre-operation. Administration starting 14 days before nerve lesion was the most effective treatment schedule for reducing autotomy in both strains.