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（P＜0.05）.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.