Interruption of the enterohepatic circulation and its effect on rat bile

Abstract
The effects of anesthesia, trauma and starvation upon the composition of bile collected immediately after operation were obviated by preparing an external enterohepatic circulatory system. After 4–7 days the cannulas were separated, bile collected in various fractions of the 1st day and analyzed for total cholic acid and cholesterol. Cholate concentration in the first 3-hour collection was high, approximately 47% of the first day's total output. Cholate concentration in hours 3–6 was about 15% of the initial period, then gradually increased to a plateau on day 3 or 4. There was little change in cholesterol concentration in the 1st day's samples, but it about doubled by day 3 or 4. Cholic acid/cholesterol ratio rapidly decreased during the first 6 hours and remained low throughout the 1st day. The initial changes occurred earlier than observed by Eriksson in samples collected immediately following operation. Changes of bile composition following interruption of the enterohepatic circulation must be considered in evaluating bile excretion studies.