Letters to the Editor |
Department of Neuroscience, Pharmacology Unit, University of Siena, Siena, Italy, ranieri@unisi.it
Department of Biology, University of Milan, Milan, Italy
Department of Neuroscience, Pharmacology Unit, University of Siena, Siena, Italy
To the Editor:
The hypothesis that endothelial-derived relaxing factor (EDRF) is nitric oxide (NO) has stimulated a wealth of research into the significance of this novel, intriguing molecule. Given its short life, many forms of storage and targeting have been postulated: among these, a pool of derivatives of NO (RSNOs) covalently bound to SH groups of proteins and low molecular weight thiols (eg, glutathione) has been identified in various biological systems. The importance of RSNOs results from the very similar biological actions exhibited by both NO and RSNOs in vivo as well as in vitro.
S-nitroso derivatives of GSH, cysteine, hemoglobin, BSA, and many other protein or nonprotein thiols are potent, fast-acting vasodilators, as well as strong inhibitors of platelet aggregation, like NO itself. Moreover, several nitrosovasodilators, such as nitrosoglycerin, have been reported to function through the formation of S-nitrosothiol intermediates.
S-nitrosothiols in biological samples have been measured by a wide spectrum of different techniques. However, in our opinion, most of these techniques are not devoid of artifacts, and the investigation of endogenous S-nitrosothiol levels, as stated by Neil Hogg, "is hampered by methodological concerns" (page 1482).1 For example, the original report of 7 µmol/L for S-nitrosothiols2 in human plasma has been more recently downgraded to very low levels.35
A recent study by Tyurin et al6 showed that the S-nitrosoprotein level (mostly S-nitroso albumin) was 9.2±1.6 µmol/L in normal human plasma and 11.1±2.9 and 9.4±1.5 µmol/L in pregnant and preeclamptic pregnant women, respectively. In particular, these
This article has been cited by other articles:
![]() |
S. C. Rogers, A. Khalatbari, P. W. Gapper, M. P. Frenneaux, and P. E. James Detection of Human Red Blood Cell-bound Nitric Oxide J. Biol. Chem., July 22, 2005; 280(29): 26720 - 26728. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Wang, J. E. Tanus-Santos, C. D. Reiter, A. Dejam, S. Shiva, R. D. Smith, N. Hogg, and M. T. Gladwin Biological activity of nitric oxide in the plasmatic compartment PNAS, August 3, 2004; 101(31): 11477 - 11482. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. T. Gladwin, X. Wang, C. D. Reiter, B. K. Yang, E. X. Vivas, C. Bonaventura, and A. N. Schechter S-Nitrosohemoglobin Is Unstable in the Reductive Erythrocyte Environment and Lacks O2/NO-linked Allosteric Function J. Biol. Chem., July 26, 2002; 277(31): 27818 - 27828. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Research Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2001 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |