L-NMMA is a relatively non-selective inhibitor of all NOS isoforms. It is the archetypal NOS inhibitor to which other inhibitors are most often compared. The Ki values for nNOS (rat), eNOS (human), and iNOS (mouse) are approximately 0.18, 0.4, and 6 µM, respectively.Formal Name:...

NG,NG-dimethyl-L-arginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS). It is formed from arginine by protein arginine methyltransferases (PRMTs) and degraded by dimethylarginine dimethylaminohydrolases (DDAHs) and alanine-glyoxylate aminotransferase 2 (AGXT2). ADMA levels are increased...

Thioarginine is a colorimetric substrate for arginase. Arginase binds to and hydrolyzes thioarginine to release 2-amino-5-mercaptovaleric acid, which reacts with DTNB (Ellman's reagent) to form 2-nitro-5-thiobenzoate and can be quantified by colorimetric detection at 412 nm as a measure of arginase activity.Formal...

L-NNA is a competitive inhibitor of nitric oxide synthase (NOS) with selectivity for the neuronal and endothelial isoforms of the enzyme. Although L-NAME is much more soluble than L-NNA in aqueous systems, a hydrolysis step is required to "activate" L-NAME, thus adding complexity to an in vivo experiment. L-NNA...