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

Abstract

SUMMARY 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 rate3 result in a decrease of water absorption and an increase in sodium and potassium secretion rates.Intestinal perfusion techniques have been widely used to study the absorption of sugars, water, and electrolytes in man (Holdsworth and Dawson, 1964;Gray and Ingelfinger, 1966; Whalen, Harris, Geenen, and Soergel, 1966;McMichael, Webb, and Dawson, 1967;Fordtran, Rector, and Carter, 1968). Neverthtless a controversy still persists about the use of a double or a triple lumen tube (Sladen and Dawson, 1968;Fordtran, 1969). Moreover, although a recent paper deals with the effects of flow rates on the absorption of glucose (Sladen and Dawson, 1969b), the exact consequences of varying flow rates have not yet been reported, especially with regard to the kinetics of glucose absorption and the movement of water and electrolytes. The present study was undertaken to investigate these two problems further. MethodsTwenty-nine subjects, aged between 25 and 65 years, were studied. They were either patients with minor

Stimulation of active and passive sodium absorption by sugars in the human jejunum.

“…They favored the concept of a direct link between sodium, sugar, and a transport site in the brush border membrane as the mechanism by which glucose stimulates sodium absorption in the human jejunum. I agree that the experimental results of Holdsworth and Dawson and Sladen and Dawson (27,28) are difficult to reconcile with data obtained previously in this laboratory.2 The only explanation I can offer is that the perfusion methods they used in these particular experiments may not reliably measure net water and sodium movement (29)(30)(31).…”

Studies of water and electrolyte movement from oral rehydration solutions (rice‐ and glucose‐based) across a normal and secreting gut using a dual isotope tracer technique in a rat perfusion model

“…17 Therefore it is possible that the net Na + secretion may relate to the¯ow rate of the perfusion solution (0.42 mL/min) in this study. However, similar studies with reduced¯ow rates (0.2 mL/min) failed to show Na + absorption.…”

Effect of 5‐hydroxytryptamine antagonists on cholera toxin‐induced secretion in the human jejunum

“…PEG in the intestinal fluid was determined according to the method of HydCn [9]. Absorption and secretion rates in the test segment were calculated from the perfusion rate and changes in PEG and electrolyte concentrations [10,11]. The perfusion studies with and without 5-HT antagonists were performed in different individuals and their basal absorption rate could not necessarily be expected to be in a narrow range [ 121.…”