INTESTINAL ABSORPTION STUDIED BY VASCULAR PERFUSION

Abstract

This chapter examines the intestinal absorption studied by vascular perfusion. Small intestine from both the rat and various species of frog has been widely employed for vascular perfusion. The frog preparation appears to be more robust than that of the mammalian small intestine. Both lumen and vascular circuits are perfused by single pass using constant flow pumps with an appropriate, gassed solution of physiological saline. Tissue edema is prevented by the addition of albumen to the vascular perfusate. The mammalian tissue requires that the vascular fluid be saturated with oxygen via an artificial lung and that the tissue be maintained at 37°C and in certain circumstances appears to require hormonal and pharmacological reagents to be added. Although this mammalian tissue clearly is more fastidious than is the frog intestine, viable preparations may be achieved, provided the problems of high resistance to blood flow and the development of necrotic changes in the tissue are adequately solved. The vascularly perfused intestine provides an excellent system for examining this exit step in an intact polarized epithelium as it is eminently suited to perturbation studies.