The study on the mechanism of macrophage culture supernatant to promote the repair of sciatic nerve injury in rats

Abstract

Objective To study the mechanism of macrophage culture supernatant in promoting the repair of sciatic nerve injury in rats. Methods The sciatic nerve injury model was made and rats were divided into 3 groups, the observation group and the model group.The control group were given saline solution.The observation group were given culture macrophage supernatant.After 12 weeks, all rats were killed and tested. Results All rats survived.The nerve amplitude[(0.16±0.04)V vs.(0.33±0.05)V, t=7.45, P=3.87E-05]and conduction velocity by electrophysiological examination[(13.22±6.23) m/s vs.(24.54±6.36) m/s, t=4.02, P=3.01E-3]in observation group had increased, and incubation period[(0.74±0.06) ms vs.(0.53±0.04) ms, t=9.21, P=7.07E-06 ]had decreased(P<0.05). The average thickness of myelin sheath[(0.48±0.07)μm vs.(1.27±0.08)μm, t=23.50, P=2.18E-09], number of nerve fibers[(0.69±0.08)/HP vs.(3.22±0.06)/HP, t=80.01, P=3.77E-14 ]and mean diameter of myelinated fibers[(1.08±0.39)μm vs.(3.63±0.42)μm, t=14.07, P=1.97E-07 ]by the morphological analysis in observation group had increased(P<0.05). The NGF mRNA[(0.13±0.04) vs.(0.42±0.05), t=14.32, P=1.68E-07 ]and Laminin mRNA[(0.07±0.03) vs.(0.38±0.06), t=14.61, P=1.41E-07 ]of Schwann cells in observation group were significantly higher(P<0.05). Conclusion Macrophage culture supernatant could promote the repair of sciatic nerve injury in rats.This effect might be the result of promoting Schwann cells secreting NGF and laminin. Key words: Macrophage; Sciatic nerve; Electrophysiological