Canine intestinal ulcer: myoelectric components and the effect of chronic hypergastrinemia.

The effects of jejunal ulcer and chronic endogenous hypergastrinemia on canine gastrointestinal myoelectric activity were investigated in three groups of dogs. All dogs were chronically implanted with electrodes on the stomach and either the duodenum or jejunum. Fasted-state myoelectric activity was monitored before and after gastroenterostomy. Two groups of dogs underwent autotransplantation of the gastric antrum to the midcolon with either gastroduodenostomy or gastrojejunostomy. The third group of dogs underwent diversion of the antroduodenum with gastrojejunostomy. Chronic hypergastrinemia was observed postoperatively in the dogs of each of the three models. Only dogs with gastrojejunostomy and antrocolic transplant developed intestinal ulcers. None of the dogs, despite the presence of ulcers in one group, demonstrated significant changes in myoelectric activity. In both gastrojejunostomy models, a trend toward lengthened interdigesive phase 2 at the expense of phase 1 was seen. No other myoelectric changes were observed and chronic hypergastrinemia had no effect on myoelectric activity in these models. We conclude; (a) experimental jejunal peptic ulcer is not marked by significant changes in interdigestive myoelectric activity and (b) chronic hypergastrinemia is not accompanied by the gastrointestinal muscle, effects reported after acute treatment with gastrin, suggesting a tolerance.