title: High peroxidative susceptibility of fish oil polyunsaturated fatty acid in cultured rat hepatocytes.
abstract: The peroxidative susceptibility in cultured rat hepatocytes of eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids (PUFA) with different numbers of double bonds was examined. Lipid peroxidation was evaluated using a newly developed HPLC procedure which includes the determination of malondialdehyde (MDA). Following exposure to 0.25-1.0 mM EPA adsorbed to BSA (EPA-BSA), cultured hepatocytes produced MDA in the fatty acid concentration- and incubation time-dependent manner. The rate of MDA production by hepatocytes varied greatly with the degree of PUFA unsaturation, and ranked as follows: docosahexaenoic acid > EPA > arachidonic acid > alpha-linolenic acid = gamma-linolenic acid > linoleic acid > oleic acid. Prolonged exposure of cultured hepatocytes to 1.0 mM EPA-BSA resulted in substantial leakage of LDH into the medium. The cell injury was associated with the loss of cellular GSH and protein thiol groups. Cotreatment of the EPA-supplemented hepatocytes with a GSH-depleting agent, diethylmaleate, promoted the cellular protein thiol loss and LDH leakage. An iron chelator, deferoxamine, and other antioxidants such as N,N-diphenyl-p-phenylenediamine and gamma-tocopherol efficiently prevented MDA production and consequently LDH leakage in the EPA-supplemented hepatocytes. These results show that peroxidative deterioration in excess of GSH-dependent defense mechanisms may occur in hepatocytes loaded with highly peroxidizable fish oil PUFA.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Sugihara
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuruta
authors.forename: Y
authors.initials: Y
authors.lastname: Date
authors.forename: K
authors.initials: K
authors.lastname: Furuno
authors.forename: K
authors.initials: K
authors.lastname: Kohashi
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D015118:Eicosapentaenoic Acid / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005395:Fish Oils / Q000378:metabolism*; D015227:Lipid Peroxidation; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012710:Serum Albumin, Bovine
chemical_list: D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D012710:Serum Albumin, Bovine; D008315:Malondialdehyde; D015118:Eicosapentaenoic Acid