Shields, Robert C.

The effect of increased portal pressure on the ileal sorption of sodium and water was determined in acute studies on anesthetized dogs. Portal pressure was controlled by an inflatable cuff placed around the vein and the movement of sodium and water into and out of a segment of the ileum was determined by use of Na22 and D2O. With the cuff in place but not inflated, exsorption of sodium (movement from blood to intestine) increased, but insorption of sodium (movement from intestine to blood) decreased, and the movement of water was little affected. Further increases in portal pressure produced a progressive increase in the rate of exsorption of sodium without having further significant effects on the insorption of sodium or the movement of water.