Enzymohistochemistry Changes Of The Denervated And Reinnervated Rabbit Orbicularis Oris Muscle In Different Time

objiective:To explore the variation regularity of succinate dehydrogenase and acetylcholinesterase after the muscle were denervated and provide experiment evidence for the clinic reparation of the peripheral facial paralysis,we observed the enzymohistochemistry change of succinate dehydrogenase and acetylcholinesterase in the rabbit orbicularis oris muscle,which was denervated and reinnervated in different time. Methods:42 well-being New Zealand rabbits were randomly equally divided into seven groups,each group has six rabbits.Rabbit orbicularis oris muscle denervated model were built.GroupⅠis control group,the ventral ramus buccal brand were shut off and then anastomose epineurium end to end without tension;the other groups were allocated according to the different reinnervation time(2week,3week,1month,3month,6month and 9month),which in turn were groupⅡ,Ⅲ,Ⅳ,Ⅴ,Ⅵ,Ⅶ.The specimen of orbicular oris muscle were gotten before operation and 3 months later after operation,frozen section, dyeing with different enzmatic histochemical stain(one with succinate dehydrogenase histochemical stain,the others with succinate dehydrogenase and esterase acetylcholine histochemical stain).Using computer image analysis technique,we observed the change of succinate dehydrogenase and esterase acetylcholinev activity after animals were denervated and neural anastomosis three months later.Results:1,All experimental groups, following the prolongation of denervation,the mean density of succinate dehydrogenase gradually degraded.Comparing with the control group,the difference has statistical significance(P＜0.05).It was no obvious difference of the mean density of succinate dehydrogenase between groupⅥand groupⅦ.As the mean density of acetylcholine esterase,there was no obvious diference between groupⅠ,Ⅱ,ⅢandⅣ.The mean density of acetylcholine esterase of groupⅤwas lower than groupⅠ,the difference has statistical significance(P＜0.05).We could not find colouration particle diameter in groupⅥandⅦ.2,Three months later after end-to-end anastomosis the nerves,there were no obvious difference of the mean density of succinate dehydrogenase between groupⅠ,Ⅱ,ⅢandⅣ.The mean density of succinate dehydrogenase of groupⅥandⅦwere lower than the control group,which has statistical significance(P＜0.05).As the mean density of acetylcholine esterase,there was no obvious diference between groupⅠ,Ⅱ,ⅢandⅣ.The mean density of acetylcholine esterase of groupⅤwas lower than groupⅠ,the difference has statistical significance(P＜0.05).3,The mean density of succinate dehydrogenase of groupⅡ,Ⅲ,ⅣandⅤafter operation was obviously higher than that before operation,the difference has statistical significance(P＜0.05).In groupⅤ,the postoperative mean density of acetylcholine esterase was higher than preoperative one (P＜0.05).Conclusion:Anastomosing the nerve of orbicularis oris muscle denervated New Zealand rabbits within three months,the muscle's metabolic function can recovery,If orbicularis oris muscle was denervated over six months,the function of muscle metabolism will be seriously damaged.The myoceptor of denervated muscle has no obvious change within one month,but after three months the myoceptor diminished.If we anastomose the nerve after three months,the myoceptor could rebound.If the orbicularis oris muscle was denervated over six months,the myoceptor vanished,it could not rebound for ever though we anastomose the nerve.So,if we repair the damaged surrounding facial nerve within three months,we can gain better effect.