IN-VIVO PLASMA-LIPID OXIDATION IN SUGAR-INDUCED RAT HYPERTRIGLYCERIDEMIA AND HYPERTENSION

Fe(II) and Fe(III) are required for the catalysis of lipid peroxidatio n through generation of reactive oxygen species that damage cell membr anes. This study investigated the effect of free radicals and lipid pe roxidation, induced by intraperitoneal injection of iron-dextran in vi vo, in the plasma of the sugar-induced hypertriglyceridemic and hypert ensive male and female rats. Lipid peroxidation was measured by the ma londialdehyde (MDA) equivalent, using a fluorescence method of 2-thiob arbituric acid reactive substances (TEARS). Iron increased TEARS gener ation by fourfold (P < .0001) in male control rats and by twofold (P < .01) in female control rats, and the difference between TEARS concent ration in female as compared with male animals was statistically signi ficant (P < .05). In the case of the sugar-fed group, iron-dextran pro duced an increase of TEARS concentration by twofold in both male (P < .001) and female rats (P < .01), and no significant difference in TEAR S concentration was observed between sugar-fed female and male rats. T he analysis of fatty acid composition by gas chromatography showed a s ignificant diminution of 50% in the proportion of arachidonic acid (C2 0:4n-6) in the male control group in comparison with the female group (P < .0001). In female control rats, a small diminution in the proport ion of C20:4n-6 and in the other polyunsaturated fatty acids was obser ved (P < .05). A significant difference in the C20:4n-6 proportion was found between the male and female group of control rats. In the sugar -fed group, iron induced a significant diminution of arachidonic acid (P < .001) in both female and male rats in comparison with the sugar-f ed group without iron.