Absorption of glucose, sodium, and water by the human jejunum studied by intestinal perfusion with a proximal occluding balloon and at variable flow rates.

A perfusion technique with a proximal occluding balloon has been used to study the absorption of glucose, sodium, and water from the human jejunum at different rates of flow. The absorption of glucose and water was significantly higher with the balloon deflated than inflated, probably because of reflux of infused solution above the point of infusion. Above the inflated balloon 0 to 4.2 ml/min of endogenous secretions could be recovered. Increasing flow rates increase the glucose absorption rate; a single relationship could be found between the glucose load and glucose absorption rate, and single values for the maximum velocity and for the half saturating load were calculated whatever the infusing rate and the initial glucose concentration. The stimulating effect of glucose on water and sodium movement increases gradually when the initial sugar concentration varies from 14 to 133 mM/1. Above this concentration a drop in water and sodium movement is observed, although the initial sodium concentration is kept constant. High flow rates result in a decrease of water absorption and an increase in sodium and potassium secretion rates.