The Study On Hepatoeyte Growth Factor Effect On Denervated Motor End-Plate And Myofiber Of Injured Facial Nerve

Objective: Hepatocyte growth factor (HGF) exhibited properties on different types of neurons, including motor, sensory and parasympathetic neurons. Facial nerve (FN) injury was a common disease in practice medicine, successful microsurgery technic and microenviroment were equally essential for peripheral nerve regeneration .But there exited some problem and repairs of injured facial nerve needed biologic repair . Function repair of injured facial nerve finally depended on repair of motor end-plate. So our study was to establish the FN transected model, in which the buccal division of FN of adult New Zealand rabbit was transected and a nerve growth chamber created to elucidate the role of HGF in the regeneration of motor end-plate and myofiber of injured facial nerve.Methods: The buccal branches of facial nerve were exposed and transected, a nerve growth chamber were created by suturing the epineurium and silicone chamber under microscope .The chambers of experimental sides(left sides of facial nerve) were injected with HGF/normal saline and that of the control sides with normal saline of same amount (10μL ) .The acetylcholinesterase (AchE) in the motor end-plate and the myofiber of injured facial nerve were analysed by using histochemical staining and image analysis techique ofter 6 and 12 weeks of operation.Results: Histochemical analysis of MEP AchE staining showed the color of MEP on HGF side was deeper than that on control side,and there was significan difference of the color of MEP between HGF and control sides after 6 and 12 weeks of operation (P<0.01).The structure of MEP on HGF side looked near normal ,while on control side it was still unmature after 12 weeks of operation.The area of the myofiber cross section on HGF side was bigger than that on control side, and there was significan difference of the area of myofiber cross section between HGF and control sides after 12 weeks of operation (P<0.01).But there was no significan difference of the area after 6 weeks of operation (P＞0.05). Conclusion: HGF within a silicone chamber enhanced the recover of MEP and myofiber in New Zealand rabbits . But recovery of metabolism of HGF needed more experiment.