Immunofluorescence of phenobarbital inducible cytochrome P-450 in the hepatic lobule of normal and phenobarbital-treated rats.
The localization of the form of cytochrome P-450 that is induced by phenobarbital was studied by direct immunofluorescence in the hepatocytes of rats pretreated with phenobarbital in comparison with saline-treated rats. Specific fluorescence was seen in the hepatocyte cytoplasm in saline- and phenobarbital-treated rats; a more concentrated halo of fluorescence was detected surrounding the nuclei in the centrilobular zones after phenobarbital treatment. In the saline-treated rats, fluorescence was barely discernible but slightly more intense in the centrilobular than perilobular zones. In phenobarbital-treated rats, fluorescence was much more intense, with a similar but much greater difference between the centrilobular and perilobular zones. The tissue distribution and induction site of this component of the cytochrome P-450-dependent microsomal system may be relevant to the site of drug toxicity and the development of chemical carcinogenesis.
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis* / Q000096:biosynthesis; D004790:Enzyme Induction; D005455:Fluorescent Antibody Technique; D005779:Immunodiffusion; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital