Double luminal and vascular perfusion of chicken jejunum: studies on 3-O-methyl-D-glucose absorption

The aims of the present study were: (1) to set up a procedure for simultaneous vascular and luminal perfusion of the chicken jejunum; (2) to assess the transport capacity of the tissue under such conditions, and (3) to study the effects of phloretin and theophylline, given through the vascular perfusate, on 3-O-methyl-D-glucose intestinal transport. The perfusion procedure described allowed the control of intestinal and vascular inflow rates and perfusion pressures so that these parameters could be adjusted to physiological values. A perfluorochemical emulsion was used as oxygen carrier for the vascular perfusate. The absorptive function of the perfused tissue was assessed by means of its ability to transport 3-O-methyl-D-glucose. Furthermore, ultrastructure preservation was evaluated by scanning and transmission electron microscopy. Results indicate that the perfused tissue kept its transport capacity and morphology intact throughout the 120-min experimental period. Moreover, no hypersecretion was observed as indicated by the constancy of perfusate volumes and perfusion pressures. Phloretin (1 mM) or theophylline (10 mM) added to the vascular perfusate markedly reduced the transfer of 3-O-methyl-D-glucose from the enterocyte to the vascular fluid without affecting the uptake from the lumen. Our results suggest that this preparation may be used as an alternative tool for the study of intestinal absorption processes in avian species, particularly when complete examination is required of the efflux of substrates from the intestinal lumen to the vascular fluid.