The effects of polyoxyethylated cholesterol on fecal bile acids and nitrogen and on cholesterol balance in rats.

Polyoxyethylated cholesterol (POEC) is a water soluble derivative of cholesterol which decreases cholesterol absorption in rats without affecting body weight, fatty acid excretion, or intestinal histology. In the present study rat feces were analyzed for cholic, deoxycholic, chenodeoxycholic, muricholic and lithocholic acid following 3 months of feeding a standard or a 2% enriched cholesterol diet with or without 1.5% POEC. In rats maintained on the cholesterol free diet, POEC increased total bile acids (mg/day) by 50% from 14 +/- 3 to 21 +/- 3 (mean +/- SEM) but only the increase in chenodeoxycholic acid was significant (P less than 0.05). The corresponding POEC effect in the 2% cholesterol diet was 31% (70 +/- 8 to 93 +/- 3, P less than 0.01). Fecal nitrogen and serum cholesterol did not vary among groups. Comparing these data with neutral steroid excretion previously determined showed that POEC in the cholesterol-free diet increased the negative cholesterol balance more than three-fold (34 +/- 7 vs 118 +/- 13 P less than 0.01). In rats fed 2% cholesterol, POEC caused a negative cholesterol balance of 222 +/- 8 compared to the control of 27 +/- 52 (P less than 0.01). The data indicate that POEC exerts complex effects in the intestinal tract which increase both bile acid and cholesterol excretion.