肉毒毒素A对大鼠肛门括约肌作用的实验研究

目的了解肉毒毒素A对肛门括约肌的作用效果,并初步探讨其作用机制。为肉毒毒素A治疗肛直肠痉挛性疾病奠定理论基础。方法取Wistar大鼠75只,随机分为3组,每组25只。分别注射肉毒毒素A、生理盐水和阿托品溶液。在注药前、后分别检测3组动物的肛周括约肌肌电图,同时行肛直肠测压。此外,作肛门括约肌的病理组织切片和苏木素-伊红(HE)染色,并在光镜下观察其组织学形态。结果治疗前3组动物间肌电图表现差异无统计学意义(P>0.05),平均电位振幅(97±36)μV,平均时限(3.8±0.9)ms。治疗后72h,肉毒素A治疗组的肌电图运动电位的平均振幅为(68±29)μV,低于阿托品组和生理盐水组;平均时限(4.6±1.2)ms,长于阿托品组和生理盐水组,差异有统计学意义(P<0.05)。肉毒毒素治疗组的肛直肠静息压、肛直肠最大自主收缩压、直肠肛门抑制反射值均低于生理盐水组和阿托品组,差异有统计学意义(P<0.05)。结论肉毒毒素A能有效降低肛门括约肌的压力,为临床治疗慢性出口梗阻型便秘疾病提供了新的方法和思路,值得进一步研究。

The effect of botulinum toxin A to anal sphineter of mouse

Objective The aim of this study was to investigate the effect of botulinum toxin A to anal sphincter and to discuss its mechanism.Methods Seventy fivce Wistar mice were separated into 3 groups randomly.Each group includes 25 mice.Botulinum toxin A through injection of anal sphincter was administered in group 1;the same volume of physiological saline and atropine were administered respectively in group 2 and group 3.Electromyogram and pressure of anal sphincter were recorded in the period of treatment.The sections of anal sphincter were stained with hematoxylin and eosin(HE)for histological analysis.Results The electromyograms and pressures of anal sphincter of mice among three groups had no significant difference before treatment(P>0.05).However,the average electric swing of anal sphincter in botulinum toxin A group was significantly lower than that in other groups after treatment(P<0.05)and the average interval time in botulinum toxin A group was significantly longer than in other groups after treatment(P<0.05).The slack pressure,contracted pressure and restraind reflection of anal sphincter in botulinum toxin A group were significantly lower than those in other groups too(P<0.05).Conclusion Botulinum toxin A is able to effectively relax the pressure of anal sphincter and is an availably medicine in treatment of proctogenous constipation.