Oxidation of adrenaline and its derivatives by S-nitrosoglutathione

An oxidizing effect of S-nitrosoglutathione toward adrenaline and its cycli c derivatives (adrenochrome and adrenolutin) is reported. The oxidation was monitored either spectrophotometrically or as oxygen uptake. Adrenaline wa s first oxidized to adrenochrome that, after isomerization to adrenolutin, was further oxidized to products monitored as fluorescence decrease. To occ ur to a significant extent, this oxidation requires copper ions that, in ad dition to a direct effect on the oxidation of the ortho-diphenol moiety, ar e also able to decompose nitrosothiols, giving rise to nitric oxide. The la tter, after interaction with oxygen and superoxide, produces nitrogen oxide s and peroxynitrite, respectively, that are important contributors to the o xidative process. In this context, catecholamines might act as regulatory f actors toward nitric oxide and its derivatives, (C) 2001 Academic Press.