胃壁注射A型肉毒毒素对大鼠胃肌电和Cajal间质细胞的影响

目的探索胃壁注射A型肉毒毒素（BTX-A）对大鼠胃肌电和胃Cajal间质细胞（ICC）的影响。方法将72只大鼠随机分为3批（2周、6周、12周）,每批24只再分为4组：对照组（Control）,胃窦注射BTX-A组（Antrum）,胃底体注射BTX-A组（Fundus）,全胃多点注射BTX-A组（Multidrop）,每组6只。分别观察大鼠胃肌电图、胃ICC的免疫组化和透射电镜。结果与对照组比较,BTX-A组胃动过缓和节律紊乱,c-kit表达减少,Cajal细胞发育不良,ICC网络结构异常;上述改变Multidrop组〉Fundus组〉Antrum组（P〈0.05）;BTX-A注射后2、6、12周,四组间差异逐渐减小,12周时,四组间部分指标差异无显著性。结论胃壁注射BTX-A在短期内可造成胃电节律紊乱和胃动过缓;BTX-A对Cajal细胞及ICC网络结构的影响是导致胃电节律紊乱、胃动过缓的重要机制之一。

Effects of introgastric injection with botulinum toxin A on gastric myoelectricity and interstitial cells of Cajal in rats

Objective To study the effect of botulinum toxin A（BTX-A） on gastric myoelectricity and interstitial cells of Cajal（ICC）.Methods Seventy-two rats were randomly assigned to 2-week group,6-week group,and 12-week group,24 in each group.Then,the rats in each group were randomly divided into control subgroup,BTX-A antral injection subgroup,BTX-A fundic injection subgroup,and BTX-A dotty injection subgroup,6 rats in each subgroup,to observe the effect of BTX-A on their gastric myoelectricity and interstucal cells of Cajal（ICC） by gastroelectromyography,immunohistochemistry,and transmission electron microscopy（TEM）.Results More significant bradygastria and rhythm disturbance,lower expression level of c-kit,severer dysplasia and worse abnormal network structure of ICC were observed by gastroelectromyography in 3 BTX-A injection subgroups than in control subgroup,which were more significant in BTX-A dotty injection subgroup followed by BTX-A fundic injection subgroup and BTX-A antral injection subgroup（P0.05）.Two,six and twelve weeks after BTX-A injection,the difference among the 4 subgroups was gradually decreased.Twelve weeks after BTX-A injection,no difference was found in the above mentioned indications among the 4 subgroups.Conclusion Gastric BTX-A injection can lead to bradygastria and rhythm disturbance.The effect of BTX-A on ICC or their network structure is one of the important mechanisms underlying bradygastria,gastric myoelectricity and rhythm disturbance.