N EXTENSIVE LITERATURE Ofl arginase activity in tissues and tissue homogenates has accumulated in recent years. Roberts (1) has studied the arginase activity of liver, kidney, and epidermis of the Swiss mouse and of a transplantable squamous cell carcinoma. He found that liver had the greatest activity, followed by carcinoma, epidermis, and kidney. Sano (2) isolated an enzyme from rabbit intest...

Extraction-As the oxidation is essentially non-specific, the plasma extract must be as free of non-lipide reducing substances as possible. All solvents should be tested occasionally for reducing residues remaining after evaporation, and redistilled if necessary. Ether should be maintained peroxide-free. The determinations reported here followed a conventional alcohol-ether extraction and subseq...