Abstract
The influence of fluorocarbon FC 43 on the metabolism of oestrogens in the isolated perfused rat liver was investigated. In comparative once-through perfusions with FC 43 emulsion or albumin solution as perfusion medium, the clearance rates of oestrone and its metabolites were determined. In perfusions with FC 43, the clearance of oestrone was lower, and the metabolites formed in the liver were more concentrated in the outflowing medium than in perfusions without fluorocarbon. This can be explained by the high affinity, even of conjugated oestrogens, to FC 43, which is established by equilibrium dialysis and partition coefficient. The results presented here show that the fluorocarbon has a strong influence of its own on the metabolism of steroids in the isolated perfused liver. Therefore, this solvent should be avoided as medium when the metabolism of steroids is studied in perfusion experiments.