Experimental Study Of Pirfenidone On Scar Formation And Nerve Function Recovery After Injury Of Sciatic Nerve In Rats

ObjectiveTo investigate the effect of pirfenidone on scar formation and nerve function recovery after sciatic nerve injury in rats.MethodsSixty healthy male SD rats were randomly divided into three groups: Control group,Lowdose group and High-dose group.Each group was divided into two subgroups: the 4th week subgroup and the 12 th week subgroup,with 10 rats in each subgroup.All rats were made into the right sciatic nerve injury model,and the three groups were fed with 0 mg/kg,25 mg/kg,and 100 mg/kg pirfenidone respectively the next day after the operation.The sciatic nerve functional index and neuroelectrophysiological were performed at the 4th and 12 th weeks after the operation,and then the collagen I was used for immunohistochemistry.Finally,the results were statistically processed.Results1.Sciatic nerve functional index:At the 4th week after operation,there was no statistical difference between the three groups(P=0.444).In the 12 th week after operation,the footprints of rats in the Control group were blurred,the footprints of the rats in the High-dose group were clear;The sciatic nerve functional index of Low-dose group was better than that of Control group(P<0.01);The sciatic nerve functional index of High-dose group was better than that of Low-dose group(P<0.01).2.Neuroelectrophysiological:At the 4th week after operation,there was no statistical difference in nerve conduction velocity(P=0.482),amplitude(P=0.623),and latency(P=0.877)between the three groups of rats(P>0.05).At the 12 th week after operation,the nerve conduction velocity of the Low-dose group was faster than that of the Control group(P=0.022);The nerve conduction velocity of the High-dose group was faster than that of the Low-dose group(P=0.016);The amplitude of the Low-dose group was higher than that of the Control group(P<0.01);The amplitude of the Highdose group was higher than that of the Low-dose group(P<0.01).The latency of Low-dose group was shorter than that of Control group(P<0.01),and that of High-dose group was shorter than that of Low-dose group(P=0.001).3.Type I collagen immunohistochemistry and image analysis:Type I collagen was stained brownish-yellow under the microscope;In the 4th and 12 th weeks after operation,the type I collagen in the Control group had obvious hyperplasia and the nerve fibers were disordered.In the 4th and 12 th weeks after operation,the Low-dose group and High-dose group,type I collagen had less hyperplasia,and nerve fibers were arranged more neatly.Image analysis shows that:At the fourth week after operation,the content of type I collagen in the Control group was higher than that in the Low-dose group(P<0.01);The content of type I collagen in the Control group was also higher than that in the High-dose group(P<0.01);There was no difference between the Low-dose group and the High-dose group(P=0.893).At the 12 th week after operation,the content of type I collagen in the Control group was significantly higher than that in the Low-dose group(P<0.01);The content of collagen in the Low-dose group was higher than that in the High-dose group(P=0.011).ConclusionPirfenidone can reduce the deposition of type I collagen at the nerve anastomosis,reduce scar formation,and have a beneficial effect on the recovery of neural function in rats.