Effects of vitamin A administration on collagen and sulfated glycosaminoglycans contents in the livers of rats treated with carbon tetrachloride.

We have investigated the effects of nontoxic doses of vitamin A on the hepatic contents of collagen and sulfated glycosaminoglycans (SGAGs) in rats chronically treated with CCl4. When the animals were treated with this retinoid before the intoxication with CCl4, liver collagen level was significantly reduced as compared with that in rats that received only CCl4 (3.31 +/- 0.40 vs 5.00 +/- 0.61 mg/gm wet liver, mean +/- SD, respectively), although no significant differences were found for the relative proportion of type III collagen related to type I collagen. The absolute increment in the total amount of liver SGAG in the vitamin A--pretreated group was followed by a more important increase in the concentration of dermatan sulfate as compared with the CCl4 group (dermatan sulfate-to-heparan sulfate ratio: 1.15 for the CCl4 group vs 1.70 for the vitamin A--pretreated group). A significant proportion of the dermatan sulfate from this last group was of higher molecular weight when compared with the dermatan sulfate found in the liver of rats that received only CCl4. Our results indicate that the pretreatment with vitamin A modifies hepatic collagen and SGAG deposition and can inhibit or delay the development of liver cirrhosis in rats chronically treated with CCl4. We speculate that this effect could be due to the changes in the fat-storing (Ito) cells phenotype induced by vitamin A.