Free radical inhibitor effect of retinol after carbon tetrachloride intoxication in the rat.

A study was conducted to explore the free radical inhibitor effect of retinol in Male Wistar rats. When retinol-deprived animals were considered retinol-depleted (after a period of 8 weeks), rats of each group, control and depleted, received an intraperitoneal injection of mineral oil (5 ml/kg body weight) or an equivalent volume of 20% carbon tetrachloride (CCl4) dissolved in mineral oil. The animals were killed by decapitation 4 h after administration of CCl4 and liver, heart, spleen, brain and testes were quickly removed. Minced tissues were homogenized and microsomes were prepared; vitamins A and E were monitored and malondialdehyde (MDA) content was estimated. Retinol-depleted rats showed an hepatic vitamin A level less than 10 pmol/mg protein, compared to control rats (15-45 pmol). In all hepatic preparations, we found low vitamin E levels (100-1300 pmol/mg protein). MDA production increased significantly in livers and hearts of retinol-depleted rats but not in brains, spleens and testes. Hearts contain less lipids and vitamin E than these latter organs, which could correlate with the highest production of MDA.