Aim: To explore the therapeutic effect of
testosterone propionate on injured sciatic nerve and its mechanism. Methods: A
total of 60 adult male Wistar rats were randomly divided into two groups:test group (
testosterone propionate-treatment group,TP group) and control group(physiological saline-treatment group,control group), 30 rats in each group. The sciatic nerve of rats was transected and sutured epineurium. According to the observing periods for 4 and 12 weeks,recovery rate of the complex muscular action potential(CMAP) and motor nerve conduction velocities (MNCV) of test group and control group were measured.Specimens in the distal ends of regenerated nerves were sectioned histologically to observe the histomorphologic changes under light microscope and the ultrastructure changes under electronic microscope. Quantitative analysis of recovery rate of myelinated fiber populations was performed. Results: At 4 weeks MNCV and CMAP of TP group were (26.74±6.54)% and (28.58±4.49)%, those of control group were (19.71±4.34)% and (18.95±5.51)%, and there were statistical differences between two groups (P<0.05). At 12 weeks, MNCV and CMAP of TP group were (54.31±12.89)% and (71.24±4.05)%, those of control group were (40.23±10.00)% and (62.95±4.89)%, and there were statistical differences between two groups (P<0.05). Quantitative analysis of the recovery rate of myelinated fiber population was (51.67±9.32)%at 4 weeks in TP group,(34.04±10.86)% in control group, (84.03±3.84)%at 12 weeks in TP group, (75.13±6.58)% at 12 weeks in control group, and the difference between two groups were all significant statistically (P<0.05). The fibers in TP group were more regular and homogeneous and the myelin sheaths were thicker than that in control group. Conclusion: TP could effectively promote the regeneration of peripheral nerves and improve the restoration of physiologic functions of regenerating nerve fibers after nerve injury.