[Selective arterial secretin injection test for localization of gastrinoma]

We have already shown that gastrinomas release gastrin when stimulated with secretin in vitro. In order to ascertain whether this is true in vivo and whether the reaction is clinically useful in the localization of gastrinomas, secretin was injected into a feeding artery of the gastrinoma in four patients, and blood samples were taken from a peripheral artery (PA) and the hepatic vein (HV) for determination of immunoreactive gastrin (IRG) and immunoreactive insulin (IRI) levels. When secretin was injected into a feeding artery of the gastrinoma, IRG rose within 40 seconds in the HV and within 60 seconds in the PA. When secretin was injected into a nonfeeder, IRG did not rise for 2 min in the PA. This test was performed to two of the postgastrectomized patients and a patient with hypergastrinemia due to atrophic gastritis. In these patients, IRG in the hepatic vein did not rise for two minutes. It was concluded that secretin directly stimulates gastrinomas to release gastrin in vivo and that the selective arterial secretin injection test is helpful in determining the location of the gastrinoma.