The role of defensin NP-1 in restoring the functions of an injured nerve trunk.

This report presents results from studies on the actions of neutrophil defensin NP-1 on the initial stage of regeneration of the lesioned sciatic nerve in rats. The effects of defensin on the growth rate and functional characteristics of regenerating nerve fibers were assessed by recording total action potentials 21 days after transection and microsurgical suturing of the nerve. These experiments showed that defensin increased the rate of growth of regenerating nerve fibers by 30%: the distance over which nerve spike conductivity was restored in the lesioned nerve increased from 7.2 +/- 1.2 (control) to 10.5 +/- 0.8 mm (experiment) from the suturing site (p < 0.05). In addition, an increase in the excitation conduction rate along the regenerating nerve fibers by 20% compared with control was observed. Overall, the results provide evidence for the positive effects of defensin on restoration of the functions of the lesioned nerve trunk.