1.   The venous effluent was collected from the cannulated ileocolic vein with a fraction collector.

2.   Total bile salts in the venous effluent were measured using direct spectofluorometry.

3.   PYY values were measured in the venous effluents collected before and during arterial infusion of TDCA.

4.   Arterial infusion of venous effluents collected before bile stimulation did not change motor activity.

5.   Venous effluents collected during infusion of bile, however, did significantly inhibit ileal motility after a very short latency.

6.   These studies showed that a humoral agent present in the venous effluent during luminal administration of bile, inhibited motor activity in isolated segments of terminal ileum.

7.   This suggested that bile inhibition of ileal motor activity was mediated by a humoral agent from the terminal ileum present in the venous effluent.

8.   Indeed, PYY and bile salt concentrations in the venous effluents increased during luminal bile infusion, though enteroglucagon and VIP concentrations did not.

9.   When PYY was arterially infused at the concentrations seen in the venous effluents, no inhibition of motility occurred.