Clinical and experimental evidence has indicated that
chronic renal failure (CRF) is related to increased
free radical production. CRF patients show increased lipid peroxidation after a progressive reduction in
vitamin E, one of the most important
antioxidants. In the present study the role of
vitamin E deficiency in lipid peroxidation was investigated in rats submitted to subtotal
nephrectomy. Male Wistar rats were divided into groups receiving different diets for a period of 45 days: SND -
sham rats submitted to a regular diet containing
vitamin E; ERD nephrectomized rats submitted to a regular diet containing
vitamin E; SDD -
sham rats submitted to a
vitamin E-deficient diet; EDD nephrectomized rats submitted to a
vitamin E-deficient diet. After 30 days the Experimental animals were submitted to 5/6
nephrectomy and the Controls were submitted to
sham operation. The
vitamin E levels of the SDD and EDD groups were significantly reduced (p < 0.05) in plasma (4.92 +/- 1.22 and 8.37 +/- 2.09 mmol/L, respectively), liver (7.57 +/- 2.72 and 9.44 +/- 2.55mg/g tissue, respectively) and kidney (8.17 +/- 2.38 and 9.40 +/- 3.10 mg/g tissue, respectively) when compared to the SRD and ERD groups. In contrast, in the EDD group the levels of
thiobarbituric acid-reactive substances, expressed as nmol/mg
protein, were significantly increased (p < 0.05) in the liver (1.41 +/- 0.27) and kidney (1.67 +/- 0.47), and
superoxide dismutase activity was significantly increased in the erythrocytes (4455.80 +/- 1322.63 Ug/Hb) compared to all other groups. The
vitamin E-deficient diet associated with subtotal
nephrectomy determined an increase in lipid peroxidation, suggesting an important role of
free radicals in the development of
chronic renal failure.