期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：12
页码：4308-4313
DOI：10.1073/pnas.0306706101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：There is mounting evidence that the established paradigm of nitric oxide (NO) biochemistry, from formation through NO synthases, over interaction with soluble guanylyl cyclase, to eventual disposal as nitrite/nitrate, represents only part of a richer chemistry through which NO elicits biological signaling. Additional pathways have been suggested that include interaction of NO-derived metabolites with thiols and metals to form S-nitrosothiols (RSNOs) and metal nitrosyls. Despite the overwhelming attention paid in this regard to RSNOs, little is known about the stability of these species, their significance outside the circulation, and whether other nitros(yl)ation products are of equal importance. We here show that N-nitrosation and heme-nitrosylation are indeed as ubiquitous as S-nitrosation in vivo and that the products of these reactions are constitutively present throughout the organ system. Our study further reveals that all NO-derived products are highly dynamic, have fairly short lifetimes, and are linked to tissue oxygenation and redox state. Experimental evidence further suggests that nitroso formation occurs substantially by means of oxidative nitrosylation rather than NO autoxidation, explaining why S-nitrosation can compete effectively with nitrosylation. Moreover, tissue nitrite can serve as a significant extravascular pool of NO during brief periods of hypoxia, and tissue nitrate/nitrite ratios can serve as indicators of the balance between local oxidative and nitrosative stress. These findings vastly expand our understanding of the fate of NO in vivo and provide a framework for further exploration of the significance of nitrosative events in redox sensing and signaling. The findings also raise the intriguing possibility that N-nitrosation is directly involved in the modulation of protein function.
