PASSAGE OF FLUID AND CERTAIN DISSOLVED SUBSTANCES THROUGH THE INTESTINAL MUCOSA AS INFLUENCED BY CHANGES IN HYDROSTATIC PRESSURE

Abstract

A. modification of Wells'' method of measuring the "absorbing force" of the intestine, used on dogs which had received a vermifuge and fasted 36 hrs. preceding the exps., showed that the absorption of glucose in aqueous solution is independent of intra-intestinal pressure between the limits of 5 and 25 cm. of solution below atmospheric. The secretion of NaCl and characteristic enzymes is increased in a linear fashion with decreasing intra-intestinal pressure. Increasing the colloid osmotic pressure in the lumen to that of blood serum does not show any influence on the absorption of water and hence the colloid osmotic pressure of the lacteal lymph cannot account for such absorption. In operated dogs with intestinal transplants the apparent absorption was increased under anesthesia, owing to inhibition of secretion by the anesthetic. The temp, of the loop under observation influenced in a complex fashion the processes of fluid exchange occurring within it. The intra-intestinal pressures employed had little if any effect on the blood flow through the loop. The method described is adaptable to the study of changes in the rate of intestinal secretion in acute exps.