title: Benzene increases the ratio of arachidonic acids to docosahexaenoic acids and inhibits the de novo synthesis of ceramide in the rat liver.
abstract: The present study investigated the effects of inhalation exposure of benzene at 0, 10, 200 and 600 ppm for 1, 2 and 4 weeks on n-6 and n-3 fatty acids and ceramide levels in the rat liver. No significant difference in the ratio of saturated fatty acid to unsaturated fatty acid was found on increasing benzene exposure levels, but the ratio of saturated fatty acid to unsaturated fatty acid decreased with increasing benzene exposure times, with the exception of the phospholipids of rats exposed to 200 and 600 ppm of benzene. A significant increase in the ratio of arachidonic acid to docosahexaenoic acid was found in the phospholipids of rats exposed to 200 and 600 ppm of benzene for 4 weeks. In our study, no change in the relative amounts of sphingomyelin in phospholipids, due to benzene exposure at 600 ppm for 4 weeks resulted in the lack of sphingomyelin turnover. However, ceramide levels in the livers of rats exposed to 600 ppm of benzene for 4 weeks were significantly reduced upon increasing the benzene concentration. This result shows that the de novo synthesis of ceramide was significantly inhibited at higher levels of benzene and that the ratio of arachidonic acid to docosahexaenoic acid in phospholipids is dose-dependently related to benzene exposure.
authors.affiliation: Department of Preventive Medicine, College of Medicine and Institute for Environmental Health, Medical Science Research Center, Korea University, Anam-dong 5 Ka, Sungbukku, Seoul 136-701, Republic of Korea.
authors.forename: Donggeun
authors.initials: D
authors.lastname: Sul
authors.forename: Ilsub
authors.initials: I
authors.lastname: Shim
authors.forename: Hosub
authors.initials: H
authors.lastname: Im
authors.forename: Namhee
authors.initials: N
authors.lastname: Won
authors.forename: Hae-Joon
authors.initials: HJ
authors.lastname: Kim
authors.forename: Eunil
authors.initials: E
authors.lastname: Lee
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D001554:Benzene / Q000494:pharmacology*; D002518:Ceramides / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D001095:Arachidonic Acids; D002518:Ceramides; D004281:Docosahexaenoic Acids; D001554:Benzene