PLASMA SECRETIN DETERMINATION AS A TEST OF GASTRIC-ACID SECRETION - EFFECT OF A MARKER PERFUSION TECHNIQUE ON VALIDATION

Objective: To examine whether plasma secretin levels can be used as a diagnostic measure of gastric acid output. Methods: A marker perfusion technique was used to quantify gastric acid output. Blood samples wer e drawn for secretin radioimmunoassay at specified intervals before an d after pentagastrin stimulation in six healthy volunteers and six pat ients suspected of having abnormal gastric acid secretion. Results: Li near relationships were found between integrated secretin response and maximal acid output as well as between peak acid output and acid outp ut at 2 h (P < 0.01). Similar correlations were also observed with sec retin levels 52, 60 and 68 min after pentagastrin stimulation. Discrim ination between low, average and high gastric acid secretors was possi ble at 52 and 60 min after stimulation. Plasma secretin did not increa se after pentagastrin stimulation in the 12 subjects when acid was con tinually aspirated, nor did correction for gastric acid loss improve t he correlation or discrimination. Conclusion: One or two measurements of plasma secretin about 1 h after pentagastrin administration may pro vide a useful quantitative estimate of gastric secretory capacity for epidemiological or clinical purposes.