Superoxide dismutase depletion and lipid peroxidation in rat liver microsomal membranes: correlation with liver carcinogenesis

• Published in: Biochimica et biophysica acta Vol. 966; no. 2; pp. 214 - 221
• Main Authors: Bartoli, Gianna Maria, Giannattasio, Bartolo, Palozza, Paola, Cittadini, Achille
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 11.08.1988; Elsevier; North-Holland
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Carcinogenesis; Copper; Copper - deficiency; Enzymes and enzyme inhibitors; Fatty Acids - metabolism; Fundamental and applied biological sciences. Psychology; Lipid peroxidation; Lipid Peroxides - biosynthesis; Liver Neoplasms, Experimental - enzymology; Liver Neoplasms, Experimental - etiology; Male; Membrane Lipids - metabolism; Microsomes, Liver - enzymology; Microsomes, Liver - metabolism; Oxidation-Reduction; Oxidoreductases; Rat liver microsome; Rats; Rats, Inbred Strains; Superoxide dismutase; Superoxide Dismutase - deficiency; Zinc - deficiency; Hepes, 4-(2-hydroxyethyl)-1-piperazineethane-sulphonic acid; Lipid peroxidation; Superoxide dismutase; Rat liver microsome; Copper; t-BOOH, tert-butylhydroperoxide; Carcinogenesis; Vertebrata; Mammalia; Rat; Enzyme; Liver; Rodentia; Lipids; Microsome; Free radical; Peroxidation
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(88)90114-6

The depletion of superoxide dismutase in the liver of rats held on a copper-deficient diet for 8 weeks induces two profound modifications in microsomal membrane characteristics. These membranes show: (1) a low degree of peroxidation induced in vitro by both endogenous (NADPH and tert-butylhydroperoxide) and exogenous sources (xanthine/xanthine oxidase) of oxygen radicals as revealed by malondialdehyde and diene-conjugate production; (2) a strong decrease of polyunsaturated and an increase of monounsaturated fatty acid content. These alterations are similar to those found in microsomal membranes from fast-growing hepatomas which exhibit a pronounced saturation of fatty acid pattern and lack superoxide dismutase. These observations support the hypothesis that during hepatocarcinogenesis the loss of superoxide dismutase causes an oxidative stress that increases cellular membrane lipid peroxidation, as a consequence of which the cell responds by synthesizing more saturated fatty acids that permanently modify cell membrane structure and properties.