THE EFFECT OF RETINOL ON THE DEVELOPMENT OF THIOACETAMIDE-INDUCED FIBROSIS IN RATS

Perisinusoidal lipocytes, which store retinol and its derivatives in their lipid droplets, play a leading role in the development of liver fibrosis (LF). Objectives. To assess the effect of retinol on the development of thioacetamide (TAA) -induced LF in rats. Material and methods. The experiment was conducted on 48 male rats, represented by 6 groups. A 10 ml/kg TAA solution (2%) was administered intraperitoneally every other day. A retinol oil solution (800 IU/kg) in sunflower oil was given once a day. Two control groups received saline solution (1) and sunflower oil (2). Light and electron microscopy of the obtained semi- and ultrathin sections of the liver tissue was performed, the relative content of the connective tissue in the liver preparations was morphometrically evaluated, the content of retinol in blood plasma and the liver was determined. Results. Morphological studies of the control animals liver revealed the presence of a typical beam structure. 4 weeks after daily administration of retinol, the beam structure of the liver persisted, but lymphohistiocytic infiltration of portal tracts and disseminated intralobular infiltration were noted; there were inflammatory foci with a large number of cellular elements; the amount of the connective tissue significantly increased. After 4 weeks of TAA administration, a pronounced inflammatory reaction was observed in the central vein region, with the penetration into the lobe, the degree of fibrosis increased with the formation of thin incomplete septs. 4-week administration of retinol after 4-week TAA exposure led to increased fibrotic processes in the liver compared to animals treated with TAA alone. 8-week administration of TAA with 4-week administration of retinol resulted in 14-fold increase in the degree of fibrosis compared to control animals. Conclusions. The application of retinol in the used experimental dose stimulates the fibrosis process in rats’ liver.