Nitrogen utilization in mice bearing Ehrlich ascites tumor treated with Acinetobacter glutaminase-asparaginase

The effects of Acinetobacter glutaminase-asparaginase (AGA) on protein and energy requirements were evaluated in mice bearing Ehrlich ascites tumors. In an initial experiment with normal mice, a zero protein diet resulted in a significant decrease in carcass nitrogen, liver nitrogen, and carcass energy relative to the animals on a normal, low, or high protein diet. In a second experiment, mice bearing Ehrlich ascites tumors were randomized into diet groups (zero or normal protein) and treatment groups (daily injections of AGA or 0.9% NaCl solution). In both treatment groups, the zero protein diet resulted in significant decreases in weight, liver nitrogen, carcass nitrogen, and carcass energy. Neither tumor nor AGA treatment affected body composition or the efficiency of nitrogen utilization. By Day 8, either the zero protein diet or AGA treatment significantly reduced ascites volume and tumor nitrogen content relative to controls. In a modification of Experiment 2, AGA treatment was stopped on Day 8, and all animals were given a normal protein diet. AGA, but not the zero protein diet, significantly enhanced ultimate survival. These experiments indicate that the requirements and utilization of energy and nitrogen are normal in mice with Ehrlich ascites tumor whether or not they are treated with AGA.