Determination of a non-volatile nitrosamine by using denitrosation and a chemiluminescence analyser

Downes, Malcolm J.; Edwards, Matthew; Elsey, T. S.; Walters, C. L.

doi:10.1039/an9760100742

Cited by 57 publications

(23 citation statements)

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“…The latter situation makes the routine measurement of blood levels in normal and disease states difficult (15,16) by standard methods, such as chemiluminescence spectroscopy (17), electron paramagnetic resonance spectroscopy (18), or differential absorbance spectroscopy of hemoglobin (19). Chemiluminescence spectroscopy has been used, in particular, to detect nitric oxide in studies of EDRF in vitro.…”

Section: Discussionmentioning

confidence: 99%

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

Stamler

Jaraki

Osborne

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

1,135

736

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We have recently shown that nitric oxide or authentic endothelium-derived relaxing factor generated in a biologic system reacts in the presence of specific protein thiols to form S-nitrosoprotein derivatives that have endotheliumderived relaxing factor-like properties. The single free cysteine of serum albumin, Cys-34, is particularly reactive toward nitrogen oxides (most likely nitrosonium ion) under physiologic conditions, primarily because of its anomalously low pK; given its abundance in plasma, where it accounts for -0.5 mM thiol, we hypothesized that this plasma protein serves as a reservoir for nitric oxide produced by the endothelial cell. To test this hypothesis, we developed a methodology, which involves UV photolytic cleavage of the S-NO bond before reaction with ozone for chemiluminescence detection, with which to measure free nitric oxide, S-nitrosodiols, and S-nitrosoproteins in biologic systems. We found that human plasma contains =7 pIM S-nitrosothiols, of which 96% are S-nitrosoproteins, 82% of which is accounted for by S-nitroso-erum albumin. By contrast, plasma levels of free nitric oxide are only in the 3-nM range. In rabbits, plasma S-nitrosothiols are present at -1 #M; 60 min after administration of NG-monomethyl-Larginine at 50 mg/ml, a selective and potent inhibitor of nitric oxide synthetases, S-nitrosothiols decreased by "40% (>95% of which were accounted for by S-nitrosoproteins, and ""80% of which was S-nitroso-serum albumin); this decrease was accompanied by a concomitant increase in mean arterial blood pressure of 22%. These data suggest that naturally produced nitric oxide circulates in plasma primarily complexed in S-nitrosothiol species, principal among which is S-nitroso-serum albumin. This abundant, relatively long-lived adduct likely serves as a reservoir with which plasma levels of highly reactive, short-lived free nitric oxide can be regulated for the maintenance of vascular tone.Endothelium-derived relaxing factor (EDRF), first described by Furchgott and Zawadzki (1), is a product of the normal endothelial cell having both vasodilatory (2) and antiplatelet (3,4) properties. Pharmacologic studies suggest that disease states as varied as septic shock (5), atherosclerosis (6), and hypoxia-induced pulmonary hypertension (7) may be associated with abnormal concentrations of EDRF in the vascular milieu. As a result of the seminal work of two groups (8, 9), this bioactive substance is believed to be equivalent to nitric oxide or a chemical congener or adduct thereof. Among the species thought of potential importance as adducts of nitric oxide are S-nitrosothiols-adducts with the sulfhydryl groups of amino acids, peptides, and proteins. We have recently shown that nitric oxide and authentic EDRF react with free thiol groups of proteins under physiologic conditions in vitro to form S-nitrosoproteins (10)-nitric oxide adducts with bioactivities comparable to EDRF but with half-lives of the order of hours. Although the facile formation of such species is intrinsically interest...

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Section: Discussionmentioning

confidence: 99%

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

Stamler

Jaraki

Osborne

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

1,135

736

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“…Given the extreme lability and facile inactivation of NO by heme iron, non-heme iron (25), superoxide anion (26), oxygen (27), and other biochemical species (28)(29), it is likely that some intermediate molecular species serves to stabilize NO and/or transfer it from its site of origin (endothelial cell) to target effector sites (e.g., vascular smooth muscle, platelets). Plasma thiols represent likely candidates for this role as they readily form thionitrites (S-nitrosothiols) under physiologic conditions by complexation with NO or by reacting with an endogenous nitrosating species (15)(16)30), are present in abundant quantities in vivo, and confer stability to the NO radical (14).…”

Section: Discussionmentioning

confidence: 99%

In vivo transfer of nitric oxide between a plasma protein-bound reservoir and low molecular weight thiols.

Scharfstein¹,

Keaney²,

et al. 1994

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Plasma albumin reacts with nitric oxide (NO) to form the bioactive adduct, S-nitroso-albumin (S-NO-albumin). The limited intracellular access of S-NO-albumin suggests the need for a vascular transfer mechanism of NO from a large plasma S-NO-albumin pool to effect biologic function. To study the role of low molecular weight (LMW) thiols in NO transfer in vivo, we administered intravenous S-NOalbumin (1-300 nmol/kg) to rabbits before and after an intravenous infusion of L-cysteine or N-acetyl-L-cysteine. S-NO-albumin produced dose-dependent hypotension that was significantly augmented by prior infusion of either LMW thiol. LMW thiol infusion significantly accelerated the rate of onset and reduced the duration of action of the hypotension induced by S-NO-albumin. The hemodynamic effects of S-NO-albumin after pretreatment with LMW thiols were mimicked by administration of the corresponding LMW S-nitrosothiol. The transfer of NO from albumin to L-cysteine was directly measured in rabbit plasma using a novel technique that couples high performance liquid chromatography to electrochemical detection. These data demonstrate that NO exchange between plasma protein thiolbound NO and available LMW thiol pools (transnitrosa-

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“…Inhaled concentrations of nitric oxide and its oxidative products were measured at the endotracheal tube by chemiluminescence. 12 The exhaled gases and those exiting the chemiluminescence instrument were collected with a Venturi device and discharged into the hospital's vacuum system. In previous studies, this system permitted precise concentrations of nitric oxide gas to be delivered, with low levels of oxidative products.…”

Section: Nitric Oxide Delivery Systemmentioning

confidence: 99%

Inhaled Nitric Oxide and Persistent Pulmonary Hypertension of the Newborn

Roberts¹,

et al. 1997

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Determination of a non-volatile nitrosamine by using denitrosation and a chemiluminescence analyser

Cited by 57 publications

References 0 publications

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

In vivo transfer of nitric oxide between a plasma protein-bound reservoir and low molecular weight thiols.

Inhaled Nitric Oxide and Persistent Pulmonary Hypertension of the Newborn

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