新西兰兔肌注肉毒毒素后肌肉及神经组织超微结构的变化研究

目的:观察新西兰兔注射肉毒毒素后,局部肌肉及神经组织超微结构变化特点,为把A型肉毒毒素充分利用于临床实践提供重要的组织形态学依据及指导依据。方法:选雄性新西兰白兔32只,随机分为A组和B组,每组各16只。选择耳前肌为注射部位,右侧耳前肌注射0.05ml(2.5U)注射用A型肉毒毒素,其中A组注射新鲜配置好的A型肉毒毒素,B组注射配置后储存2周的A型肉毒毒素;左侧耳前肌注射等量生理盐水作为对照。A、B组各随机分为2组,每组8只,分别于注射后第5天和第12周进行其肌肉组织活检,对照侧同时间点取活检。行肌肉、神经组织电镜观察。结果:肌肉电镜观察结果:在注射后早期(第5天),新鲜及储存的A型肉毒毒素对肌肉的影响无显著性差异;在注射后晚期(第12周),新鲜及储存的A型肉毒毒素比较,两者造成的肌肉萎缩程度无显著性差异。神经电镜观察结果:A型肉毒毒素注射后神经改变与上述肌肉改变同。结论:通过电镜观察注射A型肉毒毒素后的局部肌肉、神经,可以理想地观察单个目的肌肉及神经的超微结构变化特点,并且发现储存2周的A型肉毒毒素与新鲜的A型肉毒毒素比较,两者效价基本相同,为A型肉毒毒素在临床开展相关研究及应用提供了新的思路。

Changes of ultrastructure of muscle and nerve in New Zealand white rabbits after injected with botulinum toxin

Objective To observe the ultrastructural changes of muscle and nerve of New Zealand White Rabbits after injected with botulinum toxin in order to provide scientific base of histomorphology for clinical use of botulinum toxin type A. Methods Totally 32 male New Zealand White rabbits were randomized divided into group A （16） and group B （16）,and anterior auricular muscle was used forinjections. Each right anterior auricular muscle received the injection of 2.5U BTXA, Group A received the injection of freshly reconstituted BTXA while group B received the injection of stored （for 2 weeks） BTXA, and left anterior auricular muscle of the same rabbit with the same amount of saline as controls.Group A （16） were randomized divided into two groups which included 8 rabbits each.Group B （16） were randomized divided into two groups which included 8 rabbits each.Muscles and motor nerves were harvested at 5 days （early period） and 12 weeks （late period） respectively after BTXA injection, and left anterior auricular muscle was separated for histological analysis.Alterations in muscle and nerve ultrastructure were evaluated with electron microscopy. Results Degeneration findings in muscle after botulinum toxin injection revealed no significant difference between freshly reconstituted and stored toxin in the early period （the fifth day）.When stored （for 2 weeks） toxin was used, atrophic changes in the muscle were the same as the fresh toxin at 12 weeks.On nerve evaluation, the changes on nerve ultrastructure shows similar degeneration as the muscle. Conclusion Injecting Botulinum toxin type A into local muscle and evaluated with electron microscopy is a reasonable way to evaluate alterations in destination muscle and nerve ultrastructure. It seems that stored BTXA for 2 weeks and freshly reconstituted BTXA has the same initial potency, and it provides a new study and treatment for clinical research.