Nitric oxide production by endothelial cells: Comparison of three methods of quantification

Privat, Christelle; Lantoine, Frédérique; Bedioui, Féthi; Brussel, E.Millanvoye Van; Devynck, Jacques; Devynck, Marie‐Aude

doi:10.1016/s0024-3205(97)00661-9

Cited by 92 publications

(50 citation statements)

References 30 publications

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“…The identification of NO as the molecule responsible for the amperometric signal induced by histamine was assessed by inhibition of NO synthase by 1 mmol/L L-NMMA, as previously published. 23,24 In agreement with previous data obtained with the same electrode system, 22 NO oxidation at 37°C in PBS gave a dose-dependent, linear current response over the 5 to 50 nmol/L concentration range ( Figure 1). Similar electrochemical responses to NO were observed in the absence or presence of 60 g/mL 7-ketocholesterol, indicating the absence of a direct interaction between 7-ketocholesterol and NO (Figure 1).…”

Section: Measurement Of No Productionsupporting

confidence: 91%

“…22,23,[32][33][34][35] Experiments of NO release were conducted on histamine-stimulated HUVECs, an experimental system in which the release of NO has been well documented. 24,25,34,35 The real-time measurement of NO by electrochemical detection revealed for the first time that both 7-ketocholesterol and 7␤-hydroxycholesterol directly reduced the amounts of NO released by stimulated HUVECs. With the relatively short incubation periods used in the current study, no cytotoxicity was observed, indicating that the reduction of NO release cannot be explained by the cytotoxic, apoptotic properties of 7-ketocholesterol on endothelial cells that has been observed after much longer incubation periods.…”

Section: Discussionmentioning

confidence: 95%

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Inhibition by Cholesterol Oxides of NO Release From Human Vascular Endothelial Cells

Deckert

Brunet

Lantoine

et al. 1998

ATVB

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Abstract-Recent studies have demonstrated that, unlike cholesterol, cholesterol oxidized at position 7 can reduce the maximal endothelium-dependent relaxation of isolated rabbit aortas (Circulation. 1997;95:723-731). The aim of the current study was to determine whether cholesterol oxides reduce the release of nitric oxide (NO) from human umbilical vein endothelial cells (HUVECs). The amount of NO released by histamine-stimulated HUVECs was determined by differential pulse amperometry using a nickel porphyrin-and Nafion-coated carbon microfiber electrode. The effects of cholesterol (preserved from oxidation by butylated hydroxytoluene), 7-ketocholesterol, 7␤-hydroxycholesterol, 5␣,6␣-epoxycholesterol, 19-hydroxycholesterol (60 g/mL), and ␣-lysophosphatidylcholine (10 g/mL) were compared. Pretreatment of HUVECs with cholesterol, 5␣,6␣-epoxycholesterol, or 19-hydroxycholesterol did not alter histamineactivated NO production. In contrast, pretreatment with 7-ketocholesterol or 7␤-hydroxycholesterol significantly decreased NO release. The inhibitory effect of 7-ketocholesterol was time and dose dependent and was maintained in the presence of L-arginine. In the absence of serum, lysophosphatidylcholine also reduced NO production. In ionomycin-stimulated cells, pretreatment with 7-ketocholesterol did not inhibit NO release. These results demonstrate that cholesterol derivatives oxidized at the 7 position, the main products of low density lipoprotein oxidation, reduce histamine-activated NO release in HUVECs. Such an inhibitory effect of cholesterol oxides may account, at least in part, for the ability of oxidized low density lipoprotein to reduce the endothelium-dependent relaxation of arteries. Key Words: human endothelial cells Ⅲ cholesterol oxides Ⅲ histamine Ⅲ NO production T he endothelium of blood vessels regulates vascular tone by releasing endothelium-derived relaxing and contracting factors.1-3 In particular, it has now been clearly established that the endothelium-dependent relaxation of arteries induced by acetylcholine or histamine involves the release of endothelium-derived relaxing factor, 1,4 identified as NO. 5,6 Recent studies have demonstrated that alterations in vascular reactivity can be associated with cardiovascular disorders [7][8][9][10] and that arteries from hypercholesterolemic and atherosclerotic patients exhibit marked attenuation of endothelium-dependent relaxation. 7,11,12 Although the impairment of arterial relaxation at an early stage of the atherosclerotic process may constitute a crucial step in disease progression, the related molecular mechanisms remain unclear. Several studies have demonstrated that LDLs, rather than native LDLs, can mimic the impairment of arterial relaxation observed in hyperlipidemia. [13][14][15][16] Whereas in some previous studies the inhibition of endothelium-dependent relaxation was attributed to LPC, 14,15,17 other studies did not support this view. 16,18 In particular, no significant relationship between the LPC content of LDLs and their ability to reduc...

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Section: Measurement Of No Productionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 95%

Inhibition by Cholesterol Oxides of NO Release From Human Vascular Endothelial Cells

Deckert

Brunet

Lantoine

et al. 1998

ATVB

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“…Griess reaction was the method of choice to evaluate serum nitrite/nitrate levels with the following modifications. In vivo NO concentration* estimation was done via analysis of nitrites in serum without reduction of nitrates (NO -3 ) step, as it has recently been suggested that inclusion of nitrates in the determination of in vivo NO* causes an overestimation of approximately 500% than when NO was measured by the haemoglobin reaction (Privat et al, 1997). Briefly, serum samples were deproteinized with 0.6 N perchloric acid and the supernatants were assayed for nitrite concentration through recording the absorbance at 540 nm.…”

Section: Laboratory Assaymentioning

confidence: 99%

Serum concentrations of vascular endothelial growth factor and nitrite as an estimate of in vivo nitric oxide in patients with gastric cancer

̆lu¹,

Demirci²,

Ayyildiz³

et al. 1999

Br J Cancer

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SummaryThe importance of tumour angiogenesis in the process of tumour growth and progression in solid tumours has been widely accepted. Among many angiogenic factors, vascular endothelial growth factor (VEGF) has been shown to play a major role in the development and dissemination of the malignant tumours. Nitric oxide (NO) production was also observed in solid tumour tissues. NO has been reported to play an important role for the mitogenic effect of VEGF in the angiogenic process. However, little is known about the correlation between VEGF and NO in circulating levels. Therefore, we investigated serum VEGF and NO concentrations in human gastric cancers as well as healthy individuals, and examined the influence of tumour stage on circulating level of VEGF. The study consisted of 11 healthy individuals and 37 patients with primary gastric cancer who did not receive any prior therapy. Patients were categorized into four groups according to TNM classification. The level of VEGF 165 in preoperative sera of gastric cancer patients and healthy donors was assayed using the quantitative sandwich enzyme immunoassay technique. NO concentration was estimated indirectly from serum nitrite. The ANOVA test showed a significant difference in serum VEGF 165 concentrations between tumour stages (P < 0.001). A striking relationship was found between serum NO levels and tumour stage (P < 0.001). A significant difference was also seen between healthy individuals and patients with stage 1 disease. The present study suggested that large tumour burden was associated with significantly increased levels of VEGF 165 and NO.

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“…The first is based on the acidic Griess reagent assay [46][47][48][49] and the second on the conversion of oxyhaemoglobin to methaemoglobin by NO [50][51][52]. However, both methods have inherent difficulties.…”

Section: Analysis Of No Stock Solutionmentioning

confidence: 99%

Calibration of NO sensors for in-vivo voltammetry: laboratory synthesis of NO and the use of UV?visible spectroscopy for determining stock concentrations

et al. 2005

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The increasing scientific interest in nitric oxide (NO) necessitates the development of novel and simple methods of synthesising NO on a laboratory scale. In this study we have refined and developed a method of NO synthesis, using the neutral Griess reagent, which is inexpensive, simple to perform, and provides a reliable method of generating NO gas for in-vivo sensor calibration. The concentration of the generated NO stock solution was determined using UV-visible spectroscopy to be 0.28±0.01 mmol L À1 . The level of NO 2 À contaminant, also determined using spectroscopy, was found to be 0.67±0.21 mmol L À1 . However, this is not sufficient to cause any considerable increase in oxidation current when the NO stock solution is used for electrochemical sensor calibration over physiologically relevant concentrations; the NO sensitivity of bare Pt-disk electrodes operating at +900 mV (vs. SCE) was 1.08 nA lmol À1 L, while that for NO 2 À was 5.9·10 À3 nA lmol À1 L. The stability of the NO stock solution was also monitored for up to 2 h after synthesis and 30 min was found to be the time limit within which calibrations should be performed.

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Nitric oxide production by endothelial cells: Comparison of three methods of quantification

Cited by 92 publications

References 30 publications

Inhibition by Cholesterol Oxides of NO Release From Human Vascular Endothelial Cells

Inhibition by Cholesterol Oxides of NO Release From Human Vascular Endothelial Cells

Serum concentrations of vascular endothelial growth factor and nitrite as an estimate of in vivo nitric oxide in patients with gastric cancer

Calibration of NO sensors for in-vivo voltammetry: laboratory synthesis of NO and the use of UV?visible spectroscopy for determining stock concentrations

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