The Influence of Cage Bedding on the Metabolism of Sulphobromophthalein Sodium by an Hepatic Cytosol-Located Enzyme System

Abstract

The use of cage bedding prepared from pinewood shavings has been shown to be associated with an increase in the activity of sulphobromophthalein sodium (BSP) S-aryltransferase in the hepatic cytosol in rats housed on this substance. This increase was associated with enhanced secretion rates of dye into the bile due to an elevation in the biliary excretion rate of conjugated BSP. Analysis of the hepatic dye content at the time of maximal excretion of BSP into the bile indicated that this phenomenon was due to increased intrahepatic conjugation of BSP. This observation emphasizes the importance of considering environmental factors that may influence results when designing experiments on hepatic metabolism.