DETERMINANTS OF THE FLOW AND COMPOSITION OF BILE IN THE UNANESTHETIZED DOG DURING CONSTANT INFUSIONS OF SODIUM TAUROCHOLATE*

Abstract

Physiological factors affecting the flow and composition of bile may be divided into two gen- eral categories. First, the availability of bile salts (by hepatic synthesis and by reabsorption from the bowel) has a significant influence on the rate of bile production. The choleretic effect of natural bile salts and the phenomenon of enterohepatic cir- culation of these compounds were first demon- strated by Schiff in 1870 (1). These observa- tions have been confirmed by many workers since that time. It has been estimated that 85 to 90 per cent of the bile salt excreted in the bile is reabsorbed and returned to the liver (2, 3). For this reason the entry of bile itself into the duode- num provides a major stimulus for further bile production. Second, factors independent of the availability of bile salts can affect bile production. This category would include, for example, neural stimuli (4, 5), humoral agents such as secretin (6-8) and changes in vascular perfusion (5).