Origin of gastrin liberated by gastrin releasing peptide in man

Gastrin release induced by gastrin releasing peptide (GRP) in man has been studied in patients before and after complete resection of the antrum and duodenal bulb, as well as after pancreaticoduodenectomy according to Whipple. Studies in healthy subjects showed that 400 pmol/kg an hour of GRP induced a maximal release of gastrin. Infusion of this dose of GRP after a complete resection of the antrum and duodenal bulb induced a small, but significant increase in gastrin concentrations. After pancreaticoduodenectomy, however, GRP infusion had no effect on serum gastrin concentrations. In patients previously subjected to an incomplete antrectomy, GRP infusion was followed by a gastrin response considerably higher than after a complete antrectomy. Our results would suggest that GRP is capable of releasing gastrin predominantly from the antrum and the duodenal bulb, but also a small amount of gastrin from the remaining part of the duodenum. Gastrin releasing peptide infusion and determination of gastrin release may be of clinical significance in showing remaining significant gastrin pools in patients with recurrent ulceration after previous gastric resections.