Nutritional Vitamin A Deficiency Alters Antioxidant Defenses And Modifies The Liver Histoarchitecture In Rat

ANZULOVICH A.C.; OLIVEROS L; MUÑOZ E.M.; MARTÍNEZ L.D.; GIMÉNEZ MS

The Journal Of Trace Elements In Experimental Medicine

Ed. Wiley-Liss, Inc.

Año: 2000 vol. 13 p. 343 - 357

Oxidative stress and morphologic changes in the liver of female rats fed on a vitamin A-deficient diet for 3 months from 21 days of age were evaluated. Vitamin A restriction produced subclinical plasma retinol concentration (0.6 mol-L) and negligible liver retinol stores, as determined by high-performance liquid chromatography, compared to the control group, which received the same diet with 4000 IU of vitamin A (8 mg retinol as retinyl palmitate) per kg of diet. Vitamin A-deficient rats had lower body weight than control rats. No change in the liver weights was observed. In the liver of rats fed the vitamin A-deficient diet, the concentrations of thiobarbituric acid-reactive substances increased by 50%, and the activities of catalase and glutathione peroxidase increased by 30% and 40%, respectively, compared with those fed on the control diet. Liver superoxide dismutase activity did not change. Additionally, vitamin A-deficient rats showed higher liver concentrations (g/g tissue) of iron (316.03 ± 12.1 vs 203.12 ± 9.5) and lower concentrations of the antioxidant trace elements zinc (15.50 ± 1.03 vs 26.63 ± 0.25) and copper (2.27 ± 0.22 vs 4.25 ± 0.37) than those of control. Liver selenium concentration was not affected. Morphologically, livers from vitamin A-deficient rats showed a partial hepatic cord disarrangement and an increased number of hepatocytes in process of involution with piknotic nuclei and condensed cytoplasm. A reduced number of fat-hepatocytes distributed at random was observed. Portal spaces showed evidence of edema and a marked infiltration by mononuclear as well as polimorphonuclear cells. Loose portal connective tissue increased, as did the number of fibroblast-like cells in portal spaces. Vitamin A deprivation for 3 months decreased the liver retinol concentration associated with marked histological alterations in the organ, which could be due, at least in part, to the increase in oxidative stress.