Abstract

• We have investigated the effect of administation of exogenous cholic acid whether total hepatic cytochrome P-450 and b5 are altered in the bile duct-ligated rats.
  The effect of administration of exogenous cholic acid on the hepatic microsomal mixed-fuction oxidase system is various according to the administration route, dosage and date after administration.
  In normal rats, 1ml of 0.5m mol cholic acid solution per 100g body weight administrated intravenously increases hepatic content of cytochrome P-450 and b5 on the third to fifth days after injection.
  Total hepatic cytochrome P-450 and b5 are decreased after either bile duct ligation or the administration of ethinyl estradiol. In contrast when cholic acid is adminstrated simultaneously with bile duct ligation, the reduction in cytochome P-450 is relativery prevented.
  These effects are similar to the potential of phenobarbital for reversing the bile duct ligation-associated decrease in all components of the mixed function oxidase system.