Immunoreactive secretin release following taurocholate perfusions of the cat duodenum.

Perfusion of the cat duodenum with sodium taurocholate (TC), 120 mmol/l, at pH 6.1 increased the plasma immunoreactive (IRS) concentration from 2.2 +/- 0.7 pmol/l to 29 +/- 6.1 pmol/l during the first 20 min. This was accompanied by an increased pancreatic secretion of fluid, while the chymotrypsin output showed a "wash-out' phenomenon. TC increased both the bile-acid-dependent and the bile-acid-independent bile secretion. In comparison, HCl, 150 mmol/l, increased IRS from 0.9 +/- 0.5 pmol/l to 41 +/- 15 pmol/l, producing an increase in the pancreatic fluid secretion. However, only a slight increase in the bile-acid-independent bile secretion was found, and the bile-acid-dependent secretion did not change. The effects of TC on the pancreatic secretion were produced at concentrations occurring in cat hepatic bile.