Nitric oxide biological functions

Nitric Oxide Relaxes the Smooth Muscle of Blood Vessels Also Has Many Other Important Biologic Functions... 

Examples of Biological Functions of Nitric Oxide and Peroxynitrite... 

In contrast to nitric oxide, which is firmly identified in biological systems and for which numerous (but not all) functions are known, the participation of other nitrogen species in biological processes is still hypothetical. At present, the most interest is drawn to the very reactive nitroxyl anion NOT It has been shown that nitroxyl (or its conjugate acid, HNO)... 

While it is clear that NO is involved in the EDRF, there is also evidence that conjugation with thiols may occur as intermediates [47]. In 1981, Ignarro observed that NO-donating vasodilators react with cysteine to form S-nit-rosocysteine, an activator of guanylate cyclase, and suggested that the formation of unstable S-nitrosothiols was involved in the biological function of nitric oxide... 

Clearly, the short half-life of nitric oxide is an important determinant for its biological function, but the chemical basis for this short half-life is still unknown. It cannot be due to the most commonly accepted mechanism reaction with oxygen to form nitrogen dioxide. 

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