Biological Assessment of the NO-Dependent Endothelial Function

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Analytical Chemistry

Background:

• Reduced nitric oxide (NO) bioavailability is a key indicator of endothelial dysfunction, preceding cardiovascular diseases.
• Current methods for assessing NO bioavailability are indirect, measuring stable metabolites rather than NO itself.
• A direct, reliable biomarker for early endothelial dysfunction detection is needed.

Purpose of the Study:

• To introduce and validate a novel technique for directly measuring nitrosyl-hemoglobin (HbNO) as a biomarker of NO bioavailability.
• To establish the correlation between HbNO levels and endothelial function.
• To explore the utility of HbNO measurement in monitoring endothelial dysfunction in various clinical contexts.

Main Methods:

• Utilizing low-temperature electron paramagnetic resonance spectroscopy to directly quantify 5-α-nitrosyl-hemoglobin (HbNO) in human erythrocytes.
• Analyzing venous blood samples to assess HbNO levels.
• Correlating HbNO measurements with established markers of endothelial function and oxidative stress.

Main Results:

• The developed technique allows direct measurement of HbNO, reflecting vascular NO bioavailability.
• HbNO levels show a direct correlation with vascular endothelial function.
• HbNO levels are inversely correlated with vascular oxidative stress.

Conclusions:

• HbNO measurement is a promising, direct biomarker for assessing NO bioavailability and endothelial function.
• This method can aid in the early detection of endothelial dysfunction in asymptomatic individuals.
• Serial HbNO measurements can monitor disease progression and treatment efficacy in cardiovascular conditions and other endothelium-involved diseases like COVID-19.