INHIBITION OF TUMOR GROWTH BY DIETARY RESTRICTION OF SODIUM

Abstract

Previous animal studies have shown that generalized malnutrition results in the inhibition of tumor growth. We have developed an animal model in which restriction of dietary sodium in growing animals results in retardation of normal protoplasmic growth. This study evaluates the growth of a solid tumor during dietary sodium restriction. Thirty 6 wk. BDF mice were injected subcutaneously with approximately 107 viable B16 melanoma cells as determined by trypan blue exclusion technique. A salt deficient diet (less than 3μeq Na/gm) was provided ad-libitum. The drinking solution for the control group was half normal saline and for the experimental group the solution was distilled water. The animals were sacrificed 24 days after the injection of the melanoma cells. Tumor size was determined by triplicate measurements of the X and Y axes of the tumor mass. The means of the X and Y were calculated and tumor mass determined by.The tumor growth tended to be exponential in the control group and linear in the experimental group. In this experimental model, restriction of dietary sodium decreased the initiation of tumor takes and inhibited the growth of the tumor.