In duodenal ulcer patients SPV results in an increase of basal and postprandial serum gastrin levels. There is no decrease of hypergastrinemia even five years after SPV. 2. After SPV there is a significant increase in basal serum GIP levels; postprandial GIP concentrations show a faster increase after food intake. 3. Serum insulin and blood glucose concentrations are not altered by SPV.