RESUMEN
This study investigated the effect of local administration of nerve growth factor-7S (NGF-7S) on the axonal regrowth of mixed peripheral nerves through inside-out vein grafts. Sixty male Wistar rats were randomized into two groups (n = 30). A defect 12 mm long in the right sciatic nerve was created and repaired with an inside-out vein graft from the right jugular vein. NGF-7S (group A) or phosphate-buffered saline (group B; control) was locally administered daily during the first 3 weeks. Walking-track analysis and electrophysiological and histological-morphometric studies were carried out 4, 6, 8, 10, and 12 weeks postoperatively (subgroups a, b, c, d, and e, respectively, n = 6 each). Data analysis showed that 1) the recovery of motor function, as measured by walk pattern analysis and evoked muscle action potential, and 2) the orientation, number, myelin thickness, and diameter of myelinated fibers were better in the NGF-7S than in the control group. These findings present strong evidence of the beneficial effect of NGF-7S on peripheral nerve regeneration through inside-out vein grafts.