Citric Acid Metabolism in Carcinogenesis and Its

Previous studies on the calcium metabolism of epidermis undergoing carcinogenesis (@2,10, 11) have suggested the possibility that the action of one or more calcium-binding substances may ac count for the decreased calcium content in hyper plastic epidermis and in a squamous-cell carcinoma. The present investigation has been devoted to a study, in normal and cancerous tissues of the mouse, of the content of citric acid, a substance known to form slightly dissociated complexes with calcium (7). Several tumor tissues were analyzed by Dick ens (@5), who concluded that tumor tissue contains more citric acid than most normal tissues, with the exception of skin, bone, hair, and the tissues com prising the seminal vesicle. A high content of citric acid was found in the Walker @56tumor of the rat by Haven, Randall, and Bloor (8). The latter in vestigators also reported a markedly higher con tent of citric acid in the necrotic center of this tumor than in the viable periphery. These findings differ from those of Dickens (5), who found a higher citrate level in the non-necrotic portions of the Crocker sarcoma.