SIALIC ACID CONTENT OF NORMAL RAT LIVER AND OF DAB-INDUCED HEPATOMATA

Abstract
Total sialic acid content of rat livers and tumors was determined by acid hydrolysis of tissue samples, isolation on Dowex-2 columns, and reaction with thiobarbituric acid. Normal rat liver was found to contain 465 μg of neuraminic acid per g of fresh tissue. In rats bearing hepatomata induced by the feeding of p-dimethylaminoazobenzene, the tumors contained an average of 1162 μg/g, while the surrounding liver contained 587 μg/g. Treatment of tissue sections with purified neuraminidase liberated only 27–28% of the sialic acid from liver tissue, but 49% of that in the hepatomata. Paper chromatographic analysis indicated a difference between normal liver and hepatomata with respect to the types of sialic acid present.