Jejunal secretion in response to a duodenal mixed nutrient perfusion.

A multilumen balloon tube constructed to separate duodenal and jejunal perfusion segments was placed in the proximal small bowel of 6 healthy volunteers. The effect of nutrient mixture in the duodenum on net jejunal water and electrolyte flux was then determined. The duodenum was perfused with a balanced electrolyte solution before and after the nutrient perfusion. Net water flux in the perfused jejunum changed from absorption 27.0 +/- 6.0 microliter/min/cm, (mean +/- SEM) to secretion 7.7 +/- 7.3 microliter/min/cm (P less than 0.025) during nutrient perfusion. There was also net chloride secretion and decreased net absorption of Na, K, and HCO3 (P less than 0.05). The jejunal absorption of water and electrolytes before and after the duodenal nutrient perfusion was the same. Results indicate that intestinal secretion may occur under physiologic conditions at sites remote to the application of food in humans.