Concentrations of secretin and CCK in plasma and pancreatico-biliary secretion in response to intraduodenal acid and fat.

To study the effect of emulsified oleic acid on pancreatic secretion and concentrations of secretin and cholecystokinin (CCK) in plasma, eight normal subjects received three sets of duodenal perfusates containing peptone pH 6.0 or pH 2.7, with and without 20 mM oleic acid. Pancreatic secretion was measured by an indicator dilution technique. At pH 6.0, peptone and oleic acid was about as effective as peptone pH 2.7 in stimulating secretin release. However, oleic acid in addition produced a three-fold increase in plasma CCK and was five times as effective as pH 2.7 in stimulating duodenal flow. Also, at pH 2.7, oleic acid augmented pancreatic secretion and concentrations of CCK and secretin in plasma. Duodenal output of amylase and bile salts was independent of the pH of infusate. Low pH alone was a very weak stimulant of CCK release and did not stimulate output of amylase and bile. Emulsified oleic acid is a potent releaser of secretin and CCK and augments the acid-induced pancreatic secretion.