Extraction of gastrin from normal porcine pancreas

Gastrin was extracted from normal porcine pancreas by the method used by Gregory and Tracy for the extraction of gastrin from the antrum. Radioimmuno-assay was used for identification at all stages of the extraction procedure. Gastrin of pancreatic origin was eluted from a sephadex G 50 and a DEAE-collulose column at the soma position as porcine antral gastrin. In disc electrophoresis (7.5% polyacrylamide in tris-glycin buffer) we found a single band which migrated the same distance from the origin as reference gastrin (synthetic human gastrin I). Densitometircally there was also a single band. The eluate of this electrophoretic band produced an increase in gastric acid secretion after intravenous injection in the rat. A dilution series was made from the extracted fraction and radioimmunologically tested with gastrin antibodies. The individual points of the dilution curve corresponded well with the standard calibration curve of gastrin. A certain discrepancy between the small amount of gastrin found by radioimmunoassay (500 pg/g fresh pancreas) and biochemical and biological findings could probably be explained by a different sensitivity of the gastrin antibody of the radioimmunological system to pancreatic gastrin. Our results prove that there is gastrin in the normal porcine pancreas.