The nitrogen content of the lymph nodes, livers, spleens, hearts, kidneys, and “residual carcasses” of rats bearing Walker carcinoma 256 and pair-fed noncancerous rats of the same age and sex was compared at intervals during tumor growth. The “residual carcasses” and lymph nodes of the tumor-bearing rats contained less nitrogen than did the same tissues of the pair-fed controls. The hearts lost nitrogen only among those rats with relatively huge tumors. No difference in renal nitrogen content was found between the two groups. The livers of the cancerous rats acquired nitrogen during a part of the period of tumor growth but, at death, some of them contained no more nitrogen than did the livers of the pair-fed controls.
The organs and tissues that lost nitrogen while the Walker tumor was growing represent potential sources of nitrogenous building blocks for the Walker carcinoma.
This study was aided by a grant from the American Cancer Society, on recommendation of the Committee on Growth, National Research Council.