Nω-Hydroxy-L-Arginine, a Reactional Intermediate in Nitric Oxide Biosynthesis, Induces Cytostasis in Human and Murine Tumor Cells

International audienceConversion of L-arginine to L-citrulline and nitric oxide (NO) by NO synthase induced in the murine EMT-6 cells resulted in the release of a large amount of the stable reactional intermediate N omega-hydroxy-L-arginine into the extracellular medium. We have prepared [3H]N omega-hydroxy-L-arginine biosynthetically, and shown that, after its uptake, this molecule can induce cytostasis in NO synthase-deficient P-815 and U-937 tumor cells. This long-lived intermediate could behave as a supplier of NO or other toxic molecules in cell-cell interactions