nor-NOHA (acetate)

L-Arginine serves as a common substrate for both nitric oxide synthase (NOS) and arginase in the cell. NOS catalyzes the oxidation of arginine to citrulline and NO with N?-hydroxy-L-arginine (NOHA) formed as an intermediate. Arginase, on the other hand, catalyzes the hydrolysis of arginine into urea and L-ornithine. nor-NOHA (acetate) is a potent, reversible inhibitor of rat liver arginase with a Ki value of 0.5 µM, which is 20-fold lower than the Ki of 10 µM observed for NOHA.{13098} It is about 40-fold more potent than NOHA as an inhibitor of arginase from mouse macrophages, exhibiting an IC50 of 10-12 µM.{13096} nor-NOHA (acetate) is not a substrate for any of the 3 NOS isoforms and does not inhibit nNOS or iNOS.{13095, 13100}