Response of urinary lipophilic aldehydes and related carbonyl compounds tofactors that stimulate lipid peroxidation in vivo

Peroxidation of lipids results in the formation of a number of aldehydic an d other carbonyl-containing secondary degradation products. The effect of p eroxidative stimuli mediated by vitamin E deficiency, a diet high in polyun saturated fatty acids (containing cod liver oil), and carbon tetrachloride administration on urinary excretion of a number of lipophilic aldehydes and related carbonyl compounds was examined in rats. These secondary lipid per oxidation products were measured as 2,4-dinitrophenylhydrazine derivatives. All three treatments increased urinary excretion of secondary lipid peroxi dation products, although the pattern of excretion of these products varied somewhat among the treatments. Significant increases were found in butanal , hexanal, octanal, butan-2-one, pentan-2-one, hex-2-enal, hepta-2,4-dienal , 4-hydroxyhex-2-enal, 4-hydroxyoct-2-enal, 4-hydroxynon-2-enal, and a numb er of unidentified carbonyl compounds. These results suggest that urinary e xcretion of these lipophilic secondary lipid peroxidation products is a use ful and noninvasive marker of whole-body lipid peroxidation.