Enhancement of asparaginase-induced regression of the 6C3HED lymphosarcoma by protein-free diet.

A protein-free and normal protein test diet were fed to female C3H/He mice. The protein-free test diet lowered the level of asparagine in the serum of the mice and in the 6C3HED tumor. The effect of asparaginase on the 6C3HED tumor was compared in mice fed the protein-free test diet and those fed the normal protein test diet. A considerable enhancement of the asparaginase activity on the 6C3HED tumor was observed in mice fed the proteinfree test diet.