Immunoelectron microscopic localization of cytochrome P-450 isoenzyme CYP4A1 in liver, ileum and kidney of nafenopin treated male rats.


Ciba-Geigy Limited Cell Biology Group/Toxicology Services, CH-4002 Basle/Switzerland


A monoclonal antibody raised against and specific for cytochrome P-450 isoenzyme CYP4A1 was used to investigate the subcellular distribution of this enzyme in the liver, kidney and ileum of nafenopin treated rats by means of immunoelectron microscopy. In the liver and kidney, labelling was restricted to peroxisomes and mitochondria of hepatocytes and proximal tubular epithelial cells whereas in ileum, immunolabelling was exclusively detected in mitochondria of absorptive cells.