Effects of colon to antrum transposition on gastrin release and antral G-cell proliferation.

To investigate the effects of colonic mucosa on antral G-cell activity and proliferation, a colonic patch was transposed to the antrum. Thirty-nine rats were divided into 3 equal groups and underwent the following surgical procedures: Group 1: sham operation. Group 2: a standard portion (1 cm2) of the anterior surface of the antrum, including the pyloric sphincter, was removed and the defect was closed using a 10 mm segment of transverse colon shaped as a patch. Group 3 (control group): an identical procedure was carried out, closing the gastric defect with a gastro-duodenal suture. Three months after surgery, serum gastrin levels were determined by radioimmunoassay, both in fasting and freely fed animals. The antrum was then removed and examined for: counts of antral G-cell number by an immunoperoxidase method; evaluation of the cytoplasmic G-cell granule distribution (assumed as an index of gastrin turnover) by transmission electron microscopy investigation. The colon to antrum transposition significantly increased the antral G-cell density. By contrast, fasting serum gastrin levels and gastrin turnover were reduced after colon to antrum transposition, as compared with the relevant control procedure.