In an article, "Alternative Metabolic Pathways of Arginine and their Pathophysiological Roles"* Adras Hrabak and Zoltan Kukor set out how Arginase (a key ensyme in our urea cycle) may be associated with many diseases, including cardiovascular diseases, silicosis, asthma and diabetes. They review the research evidence that Arginine Derived Nitric Oxide (ADNO) inhibits the Arginase thereby ameliorating the disorders. They also note a use for L-Citrulline.
*"Arginine Amino Acid", Nova, 2011, 33 - 66