Secretin provocation: gastrin results in various clinical situations

Our previous secretin provocation studies in normal volunteers and unoperated duodenal ulcer patients suggested that the gastrin rise in gastrinoma may be an exaggeration of the normal response rather than paradoxical. We report further studies in various clinical settings having normogastrinemia (normal, n = 17; unoperated duodenal ulcer, n = 13; primary hyperparathyroidism, n = 7) and hypergastrinemia (postvagotomy, n = 5; hypochlorhydria, n = 7; achlorhydria, n = 10; chronic renal failure, n = 10; gastrinoma, n = 5). Under all nongastrinoma conditions, there were similar gastrin rises of 9-19% between 2 and 5 min after bolus intravenous GIH secretin (2 CU/kg), which fell to baseline by 8 min, except for chronic renal failure. In chronic renal failure, gastrin remained elevated from 7 to 30 min and was significantly different (p less than 0.05) at 10-30 min compared to all other nongastrinoma conditions except hyperparathyroidism. Peak rises occurred within 5 min in all entities, but only three gastrinoma patients had positive secretin provocation tests by the predefined criterion of a gastrin rise greater than 200 pg/ml. The results of secretin provocation in various clinical entities with and without hypergastrinemia further support the hypothesis that the gastrin rise in gastrinoma is an exaggeration of the normal response. The prolonged gastrin rise seen in chronic renal failure may be due to altered renal clearance, inasmuch as other hypergastrinemic states had responses similar to normal and duodenal ulcer.