(S)-Methylisothiourea sulfate

(S)-Methylisothiourea sulfate is a potent, selective and competitive inhibitor of the inducible nitric oxide synthase (iNOS). Nitric oxide synthases, composed of the constitutive and the inducible isoforms, are a family of enzymes responsible for catalyzing the production of nitric oxide (NO) from L-arginine. The inducible isoform, i.e. iNOS, can be induced in various cells, including macrophages, by a variety of agents such as endotoxin, and thereby produces NO as an immune defense mechanism. Enhanced NO formation has been implied in the pathophysiology of a variety of diseases, such as circulatory shock. Thus, (S)-methylisothiourea sulfate, as a selective iNOS inhibitor, may have considerable value in the therapy of circulatory shock of various etiologies and other pathophysiological conditions associated with induction of iNOS.

Reference:

1. Szabó C, Southan GJ, Thiemermann C. Beneficial effects and improved survival in rodent models of septic shock with S-methylisothiourea sulfate, a potent and selective inhibitor of inducible nitric oxide synthase. Proceedings of the National Academy of Sciences of the United States of America, 1994, 91(26): 12472-12476.