Influence of vagotomy upon GIP release in patients with peptic ulcer.

Twenty-two vagotomized peptic ulcer patients were studied on the influence of vagotomy on the release of GIP. Moreover, the relationship between acid output and GIP release was analyzed. These patients underwent one of the three types of operation; truncal vagotomy with pyloroplasty (TV + P) selective vagotomy with pyloroplasty (SV + P) and selective vagotomy with antrectomy (SV + A). Before and after surgery, a gastric juice study and an oral glucose tolerance test were performed on separate days. Maximum acid output in response to tetragastrin correlated significantly with integrated GIP response after oral glucose loading. In the SV + P group, the response of GIP was slightly greater after surgery. In the SV + A group, the integrated GIP response diminished postoperatively, although, after surgery, GIP reached its peak sooner. The integrated GIP response was greater in the SV + P group than in the TV + P group. The response of GIP was less in the SV + A group than in the SV + P group. These changes were insignificant. In conclusion, it is presumed that GIP release is affected by gastric acid, gastric emptying time, intestinal transit time and vagal nerve action.