The economy of the enterohepatic circulation of bile acids in the baboon. 1. Studies of controlled enterohepatic circulation of bile acids.

Abstract

A primate model with controlled enterohepatic circulation has been developed which allowed short-term evaluation of bile salt pool size, cycling frequency, and fecal losses. We found that when bile salt secretion into the small bowel was increased above 700 mumol/hr bile acid pool cycling frequency was also increased. The latter allowed short-term regulation of bile salt pool size by affecting increased fecal losses. These compensatory mechanisms were associated with a return of bile acid secretion and cycling frequency to normal usually within 12–24 hours. Conversely, during decreased bile salt secretion, regulation of bile salt pool size was accomplished by decreased pool cycling, which decreased fecal losses. Bile acid secretion into the intestine was therefore a major determinant of bile salt cycling frequency. The latter affected bile salt fecal loss to provide short-term regulation of bile salt pool when feedback regulation of bile salt synthesis was nonoperative.