MOBILIZATION OF BASOPHILE SUBSTANCE (RIBONUCLEIC ACID) IN THE CYTOPLASM OF LIVER CELLS WITH THE PRODUCTION OF TUMORS BY BUTTER YELLOW.

Butter yellow (dimethylaminoazobenzene) causes degenerative changes in liver cells accompanied by chromatolysis of cytoplasmic structures that stain with basic dyes because they contain ribonucleic acid. These changes are profoundly modified by the protein content of the diet. Chromatolysis is succeeded by focal regeneration with reaccumulation of ribonucleic acid in the cytoplasm of liver cells; these foci of basophile hyperplasia have their origin in the parenchyma surrounding portal spaces and consist of cells arranged in columns or as tubules with lumina. Hepatomas arise from foci of basophile hyperplasia and corresponding with the arrangement of cells in these foci may be trabecular or adenomatous. Butter yellow causes new formation of bile ducts which arise chiefly in the immediate neighborhood of secondary portal spaces and produce the precancerous lesion, designated cholangiofibrosis. These bile ducts may accumulate ribonucleic acid in their cytoplasm and undergo hyperplasia. Cholangiomas arise from newly formed bile ducts that are the site of basophile hyperplasia. Changes accompanying chromatolysis and basophile hyperplasia aid in the definition of structural elements of the cytoplasm and in the localization of ribonucleic acid with relation to the mitochondria.