EFFECT OF CHRONIC PROTEIN-MALNUTRITION ON HOST-TUMOR COMPOSITION AND GROWTH

A protein-deficient diet (7%) was compared to a normal protein-content diet (24%) for changes in F344 rat carcass, methylcholanthrene (MCA)-tumor growth, liver and tumor DNA and nitrogen content, and tissue DNA specific activity. Body weight gain in non-tumor-bearing protein-deficient animals was inhibited, while protein-deficient tumor-bearing rats exhibited similar growth characteristics with an increase in carcass weight loss during the final 3 days of observation (18-21 days). The concentration of host and tumor DNA was unaffected by diet whereas liver nitrogen concentration was reduced in both protein-depleted groups compared to regularly fed animals. Specific activity of tumor DNA from animals fed the protein-deficient diet was consistently greater than tumors of fully fed controls. Dietary protein restriction did not affect growth characteristics or composition of this MCA tumor, but retarded growth and lysed carcass protein of the host. These findings support efforts for nutritional repletion of the tumor-bearing host. © 1979.