[Effects of chronic exposure of ethylene oxide, especially on heme metabolism].
The changes in the cytochrome P-450 enzyme system of rat liver, lung and brain after inhalation of ethylene oxide were studied. When Wistar male rats were exposed to 500 ppm ethylene oxide three times a week for three months, they showed a suppressed gain of body weight. Therefore, the present study was done using pair-fed rats. Haematological examination revealed normocytic and normochromic anemia. Liver and renal functions were normal. The cytochrome P-450 enzyme system in the lung and brain were not affected. However, hepatic cytochrome P-450 and protoheme decreased by 28% and 19%, respectively. Hepatic total microsomal protein, cytochrome b5, NADPH-cytochrome c reductase and NADH-ferricyanide reductase were not affected. The activity of hepatic heme oxygenase showed a 2-fold increase. These results suggest that the heme moiety of hepatic cytochrome P-450 was primarily attacked by exposure of ethylene oxide and the cellular heme balance in liver was altered.
Matsuoka
M
M
Department of Environmental Toxicology, University of Occupational and Environmental Health, Kitakyushu, Japan.
D000280:Administration, Inhalation; D000740:Anemia / Q000139:chemically induced; D000818:Animals; D001921:Brain / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005027:Ethylene Oxide / Q000633:toxicity*; D006418:Heme / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D005027:Ethylene Oxide