Pulmonary cytochromes P-450 from rabbits treated with phenobarbital.
Pretreatment of rabbits with phenobarbital caused significant increases in total pulmonary cytochrome P-450 content, benzo(a)pyrene hydroxylase and 7-ethoxycoumarin O-deethylase activities and to a lesser extent in benzphetamine N-demethylase activity in lung microsomes. However, 7-ethoxyresorufin O-deethylase activity was not significantly altered. In addition, the pulmonary concentration of the cytochrome P-450-metyrapone complex was increased significantly. Column chromatography of the pulmonary monooxygenases demonstrated that in untreated and phenobarbital-treated rabbits, cytochromes P-450I and P-450II constituted the major forms of cytochrome P-450 isozymes. In addition, the chromatographic studies showed that pretreatment with phenobarbital caused an increase in the content of cytochrome P-450I, but not of cytochrome P-450II. These observations were confirmed by subjecting the pulmonary cytochromes to gel electrophoresis, and staining of the gels for protein and heme.
D000818:Animals; D001140:Aroclors / Q000494:pharmacology; D020111:Chlorodiphenyl (54% Chlorine); D002848:Chromatography, DEAE-Cellulose; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D008168:Lung / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D010634:Phenobarbital / Q000494:pharmacology*; D011817:Rabbits
D001140:Aroclors; D020111:Chlorodiphenyl (54% Chlorine); D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital