Lack of correlation between induction of adjuvant arthritis and changes in metabolism and disposition of phenylbutazone in rats.

Phenylbutazone disposition after intravenous injection of 50 mg/kg was studied in Lewis and AVN rats treated by mycobacterial adjuvant in comparison with untreated animals. Although the arthritic lesions, body weight loss and decline in albumin concentration developed only in the Lewis strain, an increase of the extrapolated volume of distribution, decline in total body clearance and prolongation of the biological half-life of phenylbutazone were found in both strains of rats. Also the content of cytochromes P-450 and b5 was reduced in both Lewis and AVN rats.