Quantitative measurements of NO reaction kinetics with a Clark-type electrode

Liu, Xiaoping; Liu, Qihui; Gupta, Era; Zorko, Nicholas; Brownlee, Emma; Zweíer, Jay L.

doi:10.1016/j.niox.2005.04.011

Cited by 26 publications

(26 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…NO stock solutions for these experiments and the work that follows were prepared as described previously3560. The preparation process was performed in a fume hood.…”

Section: Methodsmentioning

confidence: 99%

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

et al. 2017

Self Cite

View full text Add to dashboard Cite

The identity of the specific nitric oxide dioxygenase (NOD) that serves as the main in vivo regulator of O2-dependent NO degradation in smooth muscle remains elusive. Cytoglobin (Cygb) is a recently discovered globin expressed in fibroblasts and smooth muscle cells with unknown function. Cygb, coupled with a cellular reducing system, efficiently regulates the rate of NO consumption by metabolizing NO in an O2-dependent manner with decreased NO consumption in physiological hypoxia. Here we show that Cygb is a major regulator of NO degradation and cardiovascular tone. Knockout of Cygb greatly prolongs NO decay, increases vascular relaxation, and lowers blood pressure and systemic vascular resistance. We further demonstrate that downregulation of Cygb prevents angiotensin-mediated hypertension. Thus, Cygb has a critical role in the regulation of vascular tone and disease. We suggest that modulation of the expression and NOD activity of Cygb represents a strategy for the treatment of cardiovascular disease.

show abstract

“…NO stock solutions for these experiments and the work that follows were prepared as described previously3560. The preparation process was performed in a fume hood.…”

Section: Methodsmentioning

confidence: 99%

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The advantage of electrochemical NO sensors is their ability to directly detect NO concentration in solution or in biological samples with high sensitivity and a detection limit of a few nanomolar [31, 32]. This advantage allows NO electrodes to be an excellent tool for studying NO reaction kinetics, especially in biological samples.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of nitrite reduction to nitric oxide in the heart and vessel wall

et al. 2010

Self Cite

View full text Add to dashboard Cite

Nitric oxide (NO) is an important regulator of a variety of biological functions, and also has a role in the pathogenesis of cellular injury. It had been generally accepted that NO is solely generated in biological tissues by specific nitric oxide synthases (NOS) which metabolize arginine to citrulline with the formation of NO. However, over the last 15 years, nitrite-mediated NO production has been shown to be an important mechanism of NO formation in the heart and cardiovascular system. Now numerous studies have demonstrated that nitrite can be an important source rather than simply a product of NO in mammalian cells and tissues and can be a potential vasodilator drug for cardiovascular diseases. There are a variety of mechanisms of nitrite reduction to NO and it is now appreciated that this process, while enhanced under hypoxic conditions, also occurs under normoxia. Several methods, including electron paramagnetic resonance, chemiluminescence NO analyzer, and NO-electrode have been utilized to measure, quantitate, and image nitrite-mediated NO formation. Results reveal that nitrite-dependent NO generation plays critical physiological and pathological roles, and is controlled by oxygen tension, pH, reducing substrates and nitrite levels. In this manuscript, we review the mechanisms of nitrite–mediated NO formation and the effects of oxygen on this process with a focus on how this occurs in the heart and vessels.

show abstract

“…This is because the measured rate of cellular NO consumption is much greater than the rate of NO autoxidation by oxygen and the kinetic order of cellular NO consumption is different from NO autoxidation. Kinetic measurements have shown that the rate of NO consumption by parenchymal cells (hepatocytes) is first order with respect to [O 2 ] and first order with respect to [NO] [10], while NO autoxidation is second order with respect to [NO][12-14]. Recent evidence has shown that mitochondrial cytochrome c oxidase[15] and cytoglobin[16] are involved in the oxygen-dependent consumption of NO in cells.…”

Section: Introductionmentioning

confidence: 99%

Oxygen regulates the effective diffusion distance of nitric oxide in the aortic wall

Liu¹,

Collard²,

Grajdeanu

et al. 2010

Free Radical Biology and Medicine

Self Cite

View full text Add to dashboard Cite

Endothelium-derived nitric oxide (NO) is critical in maintaining vascular tone. Accumulating evidence shows that NO bioavailability is regulated by oxygen concentration. However, it is unclear to what extent the oxygen concentration regulates NO bioavailability in the vascular wall. In this study, a recently developed experimental setup was used to measure the NO diffusion fluxes across the aortic wall at different oxygen concentrations. It was observed that for a constant NO concentration at the endothelial surface, the measured NO diffusion flux out of the adventitial surface at [O2]=0 μM is around 5-fold greater than at [O2]=150 μM, indicating that NO is consumed in the aortic wall in an oxygen-dependent manner. Analysis of experimental data shows that the rate of NO consumption in the aortic wall is first order with respect to [NO] and first order with respect to [O2], and the rate constant k1 was determined as (4.0 ± 0.3)×103 M-1s-1. Computer simulations demonstrate that NO concentration distribution significantly changes with oxygen concentration and the effective NO diffusion distance at low oxygen level ([O2]≤25 μM) is significantly longer than that at high oxygen level ([O2]=200 μM). These results suggest that the oxygen-dependent NO consumption may play an important role in dilating blood vessels during hypoxia by increasing the effective NO diffusion distance.

show abstract

Quantitative measurements of NO reaction kinetics with a Clark-type electrode

Cited by 26 publications

References 42 publications

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

Mechanisms of nitrite reduction to nitric oxide in the heart and vessel wall

Oxygen regulates the effective diffusion distance of nitric oxide in the aortic wall

Contact Info

Product

Resources

About