Serum disappearance rate of gastrin-17 after vagotomy

Six duodenal ulcer patients were investigated before and after truncal vagotomy and pyloroplasty. Four doses of gastrin-17 were injected intravenously (15.625, 31.25, 62.5, and 125 micrograms/kg body weight); the gastric secretory response and the disappearance rate of gastrin were measured. After vagotomy the basal level of gastrin increased from 64 pg/ml to 106 pg/ml. When corrected for the basal levels of gastrin, the peak levels and disappearance rate of gastrin-17 were observed to be the same after vagotomy as before (half-life before vagotomy, 5.6 min; after, 5.8 min). This indicates that vagus does not influence the metabolism of exogenous gastrin-17. The gastric secretion of acid was reduced to 30% after vagotomy, which shows that there is a synergism between vagus and gastrin-17.