Plasma secretin concentrations in fasting and postprandial state in man

Abstract
Plasma immunoreactive secretin concentrations were determined in both healthy subjects and patients with duodenal ulcer. The modified radioimmunoassay method could detect significant increases in the plasma secretin concentrations when 0.05 N HCl was infused intraduodenally at a rate of 1.1 and 2.2 ml/min. The mean fasting plasma secretin concentration of 13 normal healthy subjects was 4.4±0.38 pg/ml which was significantly less (P3 solution. These observations indicate that although fasting plasma secretin levels are low, the plasma secretin levels increase significantly after ingestion of a meal. This increase appears to be attributable to an increased amount of acid delivered to the proximal duodenum, and patients with duodenal ulcer were found to release more secretin during the postprandial period than normal subjects.