Title: An enzyme histochemical and ultrastructural studyon orbicular muscle paralysis
Abstract: Objective:Inquire the pathogenesis of eye orbicular muscles paralysis and make a research on the relationship between muscle function recovery and nerve regeneration after facial nerve contusion.Methods:Gripper zygomatic and temporal branches of facial nerve to build eye orbicular muscles paralysis model in rats.Succinate dehydrogenase(SDH)of eye orbicular muscles and acetylcholinesterase(AChE)of motor end plates were examined by enzymohistochemistry and microscopic image analysis,ultrastructural change were observed by transmission electron microscope.Results:①.Muscular fiber diameter and SDH decreased at the 1st week after facial nerve contusion,decreased to the lowest at the 3rd week,began to resume at the 4th week,while nearly recovered to the normal level gradually at the 5th~8th week.②.Thearea and AchE activity ofmotor end plates decreased slightly at the 4th week,decreased continuouslly at 5~7th week,start to regenerate and AchE resumed at 8th week.At the 12th week,their morphology、area and AchE activity resume to normal level completely.③.At the 3rd after facial injury,myofibril gap of eye orbicular muscles widen,vacuolar degeneration of mitochondria occurred,synaptic vacuoles decreased.At 4~7th week,synaptic foldings shallowened and arranged in disorder even disappeared.At the 8~10th,the ultrastructure of eye orbicular muscles approximating resume normal,that of motor end plates reached to the normal level at the 12th.Conclusion:Eye orbicular muscles are mainly composed of fast contraction muscle(white muscle),which are regulated by unilateral facial nerve.While white muscle fibers are more sensitive to injury,severe reactions and restore later,so paralytic symptom of eye are worse than that of the mouth and other facial muscles in clinical above facial paralysis patients.Eye orbicular muscles could re-establish nerve and muscle join at 12th after facial nerve contusion.
Publication Year: 2007
Publication Date: 2007-01-01
Language: en
Type: article
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