Abstract
Effects of pyrimidine nucleosides upon chronic liver damage of rats induced by repeated administration of CCl_4 were observed. Administration of daily 10mg/kg of uridine or cytidine inhibits the increase of liver hexosamine and collagen and reduces te decrease of protein, copper-protein (p-phenylenediamine oxidase activity) and ornithine carbamyl transferase activity in liver, and thus prevents the liver cell necrosis and fibrosis. Histological findings, such as vacuolar degeneration of liver cells, central necrosis of liver lobule, cell infiltration, proliferation of connective tissue and collagen fibres, were also observed being reduced by the treatment with these nucleosides. Electron-microscopically, cytidine prevents the decrease of Palade granule of endoplasmic reticulum in damaged liver cells. Considering the fact that the decrease of uracil nucleotides and the disturbance of de novo synthesis of pyrimidines are observed in chronically damaged liver, it is possible to assume that uridine and cytidine, being incorporated into nucleotides, are utilized as nucleotide coenzymes and as nucleic acid precursors, and thus controlling metabolic abnormalities in damaged liver, act effective upon fatty degene-ration and cirrhotic process of the liver.
