Walker Carcinosarcoma 256 Tissue as a Dietary Constituent. III. Sodium as a Factor in Stimulation of Water and Food Intake and Growth in Tumor-Bearing Rats

Abstract

Lyophilized tumor (T) tissue used as a source of N in the diet can stimulate food intake and weight gain in T-bearing rats that have reached a weight plateau on a 20% casein (C-20) diet. Water-soluble and water-insoluble fractions of lyophilized, defatted Walker carcinosarcoma 256 tissue were prepared, incorporated into diets, and fed to rats bearing Walker 256 T. The stimulatory properties of these fractions were compared to those of whole T tissue. The water-insoluble fraction produced a delayed stimulation resulting in less eventual body-weight gain but equal T weights. A marked stimulation by the water-soluble fraction was observed similar to that of whole T. This activity was due to the Na+ content. Increasing the Na content of the C-20 diet by added NaCl resulted in markedly increased water intake, food intake, and weight gain, less adrenal hypertrophy, larger T, and increased hydration of the carcass. Whole T tissue showed these same effects on a somewhat lower food intake. On a pair-fed basis, whole T tissue showed a greater growth stimulation than C-20 + NaCl, which suggests that there may be an additional factor in T tissue besides the Na+.