Effect of ileal infusion of glycochenodeoxycholic acid on segmental transit, motility, and flow in the human jejunum and ileum.

The hypothesis that the presence of glycochenodeoxycholic acid (GCDC) in the human Ileal bile acid concentrations showed a 54.0 (9.3)% absorption of glycochenodeoxycholic acid by the been tested in healthy volunteers. Mean transit times, flow rates and intraluminal pressures in a 40 cm jejunal segment proximal (n = 6) and a 40 cm ileal segment distal (n = 6) to a GCDC infusion port were measured. During GCDC infusion (60 mumol/min) jejunal and ileal transit were markedly (p less than 0.05) delayed (31.6 (7.7), mean (SEM) v 14.5 (3.8) min and 37.0 (5.7) v 21.0 (3.5) min, respectively), segment volumes increased (141.1 (30.2) v 59.2 (9.9) ml and 173.2 (26.3) v 83.9 (9.5) ml; p less than 0.05), while flow rates did not change significantly (4.6 (0.6) v 4.5 (0.6) ml/min and 4.8 (0.5) v 4.2 (0.3) ml/min, respectively). Ileal pressures (distal to the GCDC infusion port) decreased (p less than 0.05) promptly (1.0 (0.1) min) after the start of GCDC infusion. Inhibition of jejunal motility was more gradual and reached significance (p less than 0.05) only 30 min after beginning of the infusion. Ileal bile acid concentrations showed a 54.0 (9.3)% absorption of glycochenodeoxycholic acid by the 40 cm ileal segment. These observations suggest the existence of an intestinal control mechanism in healthy man, whereby presence of glycochenodeoxycholic acid in the ileum inhibits motility and delays transit in the jejunum and ileum.