The effect of gastric inhibitory polypeptide on human jejunal water and electrolyte transport.

Using a triple-lumen gut perfusion technique, the net flux of water and electrolytes in the jejunum of 5 healthy volunteers was measured before, during and after an intravenous infusion of gastric inhibitory polypeptide (GIP). The dose of GIP used (1 mug/min for 30 mins) has previously been shown to raise serum GIP levels to physiological levels achieved in normal subjects after a meal. During GIP infusion, net water Na, K, and HCO3 absorption was significantly reduced and chloride flux was switched from absorption to secretion when compared to pre- and post-GIP control periods (p less than 0.001).