Responses of cytochrome P-450 isozymes of rat lung to in vivo exposure to ozone.
The effects of 2 weeks exposures of rats to 0.2 ppm O3 on pulmonary cytochrome P-450 isozymes were investigated. Two main types of cytochrome P-450 isozymes (cytochromes P-450FI and P-450FII) were separated from lung microsomes of control rats on an anion exchange cellulose column. Antibody raised against cytochrome P-450b, which is the main isozyme of liver obtained from phenobarbital-treated rats, cross-reacted with pulmonary cytochrome P-450FII, but not with cytochrome P-450FI. Ozone exposures caused increases in the content of both cytochromes P-450FI and P-450FII to the same extent two times greater than those of control rats without changes in immunological properties of these isozymes. No pulmonary cytochrome P-450 isozyme other than cytochromes P-450FI and P-450FII was observed in eluate through anion exchange column chromatography. These results indicate that increases in the content of pulmonary cytochrome P-450 of rats exposed to O3 can be ascribed to increase in constitutive types of the isozymes, but not to induction of other types of isozyme.
Takahashi
Y
Y
Basic Medical Sciences Division, National Institute for Environmental Studies, Ibaraki, Japan.
Miura
T
T
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D008168:Lung / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D009251:NADPH-Ferrihemoprotein Reductase / Q000302:isolation & purification / Q000378:metabolism; D010126:Ozone / Q000633:toxicity*; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D007527:Isoenzymes; D008748:Methylcholanthrene; D010126:Ozone; D003577:Cytochrome P-450 Enzyme System; D009251:NADPH-Ferrihemoprotein Reductase; D010634:Phenobarbital