MECHANISMS OF BILE SECRETION

Abstract

The formation of bile in the liver is a complicated process. One group (A) of substances appears in bile in the same concentrations as in blood; this includes glucose and the chlorides of sodium and potassium. A second group (B) appears in bile concentrated as much as hundredfold; this group includes the bile salts, bile pigments, and certain test substances like sulfobromophthalein. A third group (C) is retained in the blood and appears in the bile only in very low concentrations, if at all. Groups A and B are controlled independently of each other, and substances of group B are transferred from blood to bile by an active secretory process. The transfer of sulfobromophthalein involves some active secretion, some storage, and some chemical conversion with other phenomena in addition. Since better understanding of these processes is essential to the interpretation of functional tests and the planning of treatment, further fundamental research is needed.