The influence of bile on the alkaline phosphatase activity of intestinal lymph.

A marked increase in the activity of alkaline phosphatase of intestinal lymph following feeding has previously been found in the rat (1). Because this increase was much greater than that found in the plasma of the intact rat after feeding and because the activity of this enzyme decreased to very low levels in the plasma of rats from which lymph was being drained, it appeared that the small intestine is normally an important source of the alkaline phosphatase of the plasma in this animal. It has been suggested that the intestine might also be an important source for the elevated levels found in the plasma of animals with obstructive jaundice (2). Dalgaard (3) has recently shown, however, that this is unlikely, since elevated plasma levels could be produced by ligation of the common bile duct in dogs which had previously undergone enterostomy. We have reinvestigated the effect of fat-containing and fat-free meals on the alkaline phosphatase activity of intestinal lymph of the rat under somewhat more favorable conditions for both enzyme measurement and lymph flow. The increase appears to be considerably larger after fat-containing meals than after fat-free meals in the normal rat. If, however, bile is diverted from the intestine either by a biliary fistula or by ligation of the bile duct, an increased amount of alkaline phosphatase is not released into the intestinal lymph after feeding.