Effects of taurocholic acid on gastric acid secretion and gastrin release

Abstract

Serum gastrin concentrations and Heidenhain pouch acid outputs were measured in dogs before and during perfusion of denervated antral pouches with 10 mM taurocholic acid. Perfusates were maintained at an osmolality of 300 mosM, with pH adjusted to 7.0, 3.0, or 1.0. Results were compared with those obtained with antral perfusion of isosmolar solutions at the same pH, but not containing taurocholic acid, and with 0.5% acetylcholine, pH 7.0. Antral pouch perfusion with taurocholic acid at pH 3.0 and 7.0 stimulated both Heidenhain pouch acid output and gastrin release into the circulation. Perfusion of antral pouches with taurocholic acid at pH 1.0 produced no increases in serum gastrin concentrations nor in acid output from the Heidenhain pouches. Peak acid outputs and serum gastrin concentrations produced by perfusion of the antral pouches with 10 mM taurocholic acid at pH 3.0 and at pH 7.0 approximated 15–20% of those achieved with 0.5% acetylcholine (pH 7.0). Results of this study demonstrate the capacity of perfusion of the antrum with taurocholic acid at pH 3.0 and pH 7.0 to stimulate gastrin release and confirm previous observations that antral perfusion with taurocholic acid stimulates gastric acid output. The stimulatory effects of taurocholic acid were not noted with antral perfusion of pH 1.0, a pH known to inhibit gastrin release in response to almost all stimuli. These results are consistent with the conclusion that release of gastrin is the mechanism by which antral pouch perfusion with bile acids induces gastric acid secretion.