Abstract: | The effect of dietary L-arginine on the growth and development of transplantable Ehrlich Ascites tumor cells was examined. Growth of tumor bearing mice was significantly inhibited by feeding a purified casein diet supplemented with 5% arginine. This diet significantly reduced the total number of free tumor cells growing in the peritoneal cavity of mice. Total free tumor cell RNA, DNA, and protein were also significantly reduced. Supplemental arginine approximately doubled the length of time for 50% death of tumor bearing mice. Arginine did not alter respiration as measured by glucose or citrate oxidation. Varying the concentration of supplemental dietary arginine revealed that 3% arginine also significantly retarded the growth of Ehrlich Ascites Tumor Cells. Tumor ornithine decarboxylase activities were significantly reduced by dietary arginine supplementation. Supplemental dietary arginine at 3 or 5% did not significantly affect the growth of non-tumor bearing mice. Dietary arginine may play a critical role in growth of normal as well as neoplastic tissue. |