[Mechanism of the hypobilirubinemic effect of prednisolone and some pyrazolone derivatives].

The effects of prednisolone (1 mg/kg), nicophezone (10 mg/kg), phenylbutazone 30 mg/kg) and antradion (60 mg/kg) on choleresis and bilirubin passage with bile was studied in intact and CCl4-poisoned rats (by using hemolyzed blood loads). Intravenous administration of hemolyzed blood to intact animals was shown to be attended by an increased excretion of bilirubin with the bile. When superimposed upon the CCl4 poisoning--the excretion of bilirubin diminishes. The study compounds stimulated the passage of bilirubin with the bile following introduction of hemolyzed blood both in intact animals and in the ones with the CCl4-damaged liver. The data thus made available are used in interpreting the mechanism underlying the hypobilirubinemic effect of the compounds.