Influence of phenobarbital, chlorpromazine, progesterone and phenylbutazone on the biliary cholesterol excretion in rats.

Bile flow and biliary excretion of free cholesterol were estimated after single and/or repeated i.p. administration of phenobarbital (60 mg/kg b. w.), chlorpromazine (40 mg/kg b.w.), progesterone (50 mg/kg b.w.), and phenylbutazone (100 mg/kg b.w.) in male Wistar rats. The drugs enhanced the biliary cholesterol excretion after both single and repeated administration, whereas only phenobarbital and phenylbutazone pretreatment increased the bile flow. Bile acid excretion was concomitantly enhanced only after phenylbutazone pretreatment. These results suggest that cholesterol output in rats may be widely bile acid independent and can be influenced by different drugs.