大鼠慢传输型便秘模型的建立及其结肠肌电变化检测

Changes of colonic myoelectric activity in a rat model of slow transit cons tipation

目的 拟应用复方苯乙哌啶建立一种大鼠慢传输型便秘模型 ,并采用电生理技术检测便秘大鼠的结肠肌电变化情况 ,旨在为慢传输型便秘的研究建立一种理想的动物模型 ,并从电生理的角度初步探讨慢传输型便秘的发病机制。方法 健康Wistar大鼠 74只 ,分 2期进行实验。第 1期 4 2只 ,随机分 7组 ,每组 6只 ,筛选药物剂量 ;第 2期 32只 ,随机分为对照组、模型组 ,每组 16只 ,根据所选药物剂量 ,建立大鼠慢传输型便秘模型。 12 0d后 ,采用活性炭灌胃法测定肠道传输速度 ,同时采用电生理技术进行结肠肌电检测。结果 慢传输型便秘模型组大鼠肠道传输速度与对照组相比明显减慢 ,首粒黑便排出时间为 (35 6± 5 0 )min ,较对照组大鼠显著延长 [(2 4 9± 35 )min ,P <0 .0 1]。模型组大鼠结肠慢波出现双向改变 ,部分大鼠结肠慢波频率明显减慢 (P <0 .0 1) ,振幅增加 (P <0 .0 1) ,波形仍表现为不规则的近似正弦波样曲线 ;部分大鼠结肠慢波频率出现快速性改变 (P <0 .0 1) ,振幅强弱不等 (P <0 .0 1) ,波形较不稳定 ,且出现基线位移。结论 成功建立了大鼠慢传输型便秘模型 ,该模型简单经济 ,可重复性强。本研究表明结肠慢波异常可能是导致慢传输型便秘结肠传输减慢的重要因素。

Objective To develop a model of slow transit constipation by feeding rats with diphenoxylate, and study the pathogenesis of slow transit constipation by investigating the changes of colonic myoelectric activity in the rats.Methods Seventy-four healthy Wistar rats were used in th e study. First,42 rats were used to choose the fittest dosage of diphen oxylate to develop slow transit constipation model. Then, 32 rats were randoml y divided into control group and model group of slow transit constipation. After 120 days, colonic myoelectric activity and the time of colonic transit were recorded.Results The movement of contents from the pro ximal to the distal colon and rectum in model rats was significantly slower than that in normal rats. In model rats,the time of discharge of the first black fae ces was 356±50min,significantly longer than that in normal rats [(249±35) min ,P<0.01].In some model rats, the frequency of colonic slow wave decreas ed [(5.55±1.20) /min vs (13.20±1.09) min in control group, P< 0.01] and the amp litude increased [(0.43±0.05) mv vs (0.19±0.02) mv in control group, P< 0.01],and their slow wave pattern was irregular. In the other model ra ts, the frequency of colonic slow wave increased[(30.85±3.86) /min vs ( 13.20 ± 1.09) /min for control group, P<0.01] and the amplitude was variable [(0. 21±0.03) mv vs (0.19±0.02) mv for control group, P<0.01], and their slow wave patte rn was also irregular.Conclusions A rat model of slow transit c onstipation has been successfully developed.Abnormality of colonic myoelectr ic activity may be one of the mechanisms of slow transit constipation.