LOCALIZATION OF RIBONUCLEIC ACID IN THE CYTOPLASM OF LIVER CELLS

The attempt has been made to determine the character of the basophile material that occurs normally in the cytoplasm of liver cells and accumulates in association with the hyperplasia of liver cells and of newly formed bile ducts when the azo dye butter yellow is administered to white rats. This substance in the normal liver cells, in the parenchymatous foci of basophile hyperplasia that are precursors of hepatomas, and in the hyperplastic basophile ducts that precede the cholangiomas produced by butter yellow has the characteristics of ribonucleic acid. It absorbs ultraviolet radiation of wave length 2537 Å. It does not, like desoxyribonucleic acid, give the Feulgen reaction. It is removed from the cytoplasm by ribonuclease, and precipitation with lanthanum acetate protects it against the enzyme.