Combined used of nerve growth factor and adenosine triphosphate for repair of peripheral nerve injury and its influence on the denervated muscle

Objective To investigate the unification effect of rat nerve growth factor(NGF)and adenosine triphosphate(ATP)on repair of the peripheral nerve injury and the denervated muscle.Methods Ninety-six healthy SD rats weighing(250±15)g were randomly divided into NGF+ATP group,NGF group,ATP group and NS group.The sciatic nerves were cut for 3 mm,and were connected with silicone tube to create the nerve regeneration room.Then,all rats were intraperitoneally injected with NS0.4ml,ATP0.4ml(1 mg/ml),NGF 0.4 ml(0.2 μg/ml),NGF+ATP 0.4 ml(ATP1 mg/ml,NGF 0.2 μg/ml)separately once every three days.Six rats from each group were selected at 2,4,6 and 8 weeks after operation for sciatic nerve index(SFI)detection,gross observation and electrophysiological test;the specimens were obtained from the sacrificed rats for nerve regeneration,gastrocnemius muscle wet weight,fiber diameter and cross-sectional area of the gastrocnemius muscle(by HE staining).ResultsAt 2,4,6 and 8 weeks after operation,every six rats were chosen to be tested.The SFI,nerve conduction velocity and wet weight of the muscle of NGF+ATP group were better than those of the other three groups(P ＜ 0.05).The swelling of the rat toes of NGF+ATP group was slighter than that of NGF group and ATP group,with no loss of toes found in NGF+ATP group.At the 2nd week after operation,new nerve fibers were observed in the regeneration room,with no connection of the nerve fibers.The nerve fibers crossed the regeneration room at 4,6 and 8 weeks after operation.Compared with other three groups,the nerve growth condition was better in NGF+ATP group,with slighter adhesion and inflammation of nerve fibers.The growth condition of the nerve fibers of NGF group was better than ATP group,and that of NGF group and ATP group was better than NS group.At 2,4,6 and 8 weeks after operation,the electrophysiological condition and wet weight of muscle in NGF group was better than those in ATP group.While the SFI,the cross area and diameter of the muscle in NGF group were better than ATP group at 4,6 sand 8 weeks(P ＜ 0.05).All the parameters in NGF group and ATP group were better than NS group at each time point(P ＜ 0.05).Conclusions(1)The unification effect of NGF and ATP exert apparent effect in repair of the injured nerve and on the denervated muscle.Combined application of NGF and ATP is superior than NGF or ATP used alone.(2)A certain effect of ATP in repair of the injured nerve and on the denervated muscle is detected,but it is inferior to NGF and NGF+ATP. Key words: Sciatic nerve; Nerve growth factor; Adenosine triphosphate