Abstract
S-Nitrosation of cysteine residues plays an important role in nitric oxide (NO) signaling and transport. The aim of the present study was to investigate the role ofS-nitrosothiols as a storage form of NO, which may account for the long-lasting effects in the vasculature. Rat aorta exposed to S-nitrosoglutathione (GSNO) displayed, even after washout of the drug, a persistent increase in cysteine-NO residues (detected by immunostaining using an antiserum that selectively recognized S-nitrosoproteins) and in NO content (detected by NO spin-trapping), a persistent attenuation of the effect of vasoconstrictors, and a relaxant response upon addition of low molecular weight (LMW) thiols. Rat mesenteric and porcine coronary artery exposed in vitro to GSNO, as well as aorta and mesenteric arteries removed from rats treated in vivo with GSNO, displayed similar modifications of contraction. In isolated aorta exposed to GSNO, the decrease of the contractile response and the relaxant effect of LMW thiols were both blunted by NO scavengers (oxyhemoglobin or 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) or by a cyclic GMP-dependent protein kinase inhibitor (Rp-8-bromoguanosine-3′,5′-cyclic monophosphorothioate). In these arteries, mercuric chloride (which cleaves the cysteine-NO bond) exerted a transient relaxation, completely abolished the one of LMW thiols, and blunted the increase in cysteine-NO residues and NO content. Together, these data support the idea thatS-nitrosation of cysteine residues is involved in long-lasting effects of NO on arterial tone. They suggest thatS-nitrosation of tissue thiols is a mechanism of formation of local NO stores from which biologically active NO can subsequently be released.
Footnotes
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This work was partially supported by a grant from Fondation de France. J.L.A. is the recipient of a fellowship from CAPES-Brazil and IL (visitor scientist from Institute of Chemical Physics, Russian Academy of Science, Moscow) from ARC.
- Abbreviations:
- NO
- nitric oxide
- NOS
- nitric-oxide synthase
- LMW
- low molecular weight
- GSNO
- S-nitrosoglutathione
- NAC
- N-acetylcysteine
- DETC
- diethyldithiocarbamate
- PBS
- phosphate-buffered saline
- EPR
- electron paramagnetic resonance
- NE
- norepinephrine
- PHE
- phenylephrine
- p-HMBA
- para-hydroxymercuribenzoic acid
- p-CMPS
- para-chloromercuriphenylsulfonic acid
- ELISA
- enzyme-linked immunosorbent assay
- BSA
- bovine serum albumin
- g-BSA
- glutaraldehyde-conjugated bovine serum albumin
- U46619
- U46619, 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin
- oxyHb
- oxyhemoglobin
- carboxy-PTIO
- 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide
- MANOVA
- multivariate analysis of variance
- ANOVA
- analysis of variance
- Rp-8-Br-cGMPS
- Rp-8-bromoguanosine 3′,5′-cyclic monophosphorothioate
- SOD
- superoxide dismutase
- Received November 4, 2002.
- Accepted February 7, 2002.
- The American Society for Pharmacology and Experimental Therapeutics
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