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11:28
Analytical Techniques for Assaying Nitric Oxide Bioactivity
Published on: June 18, 2012
Specific S-nitrosothiol (thionitrite) quantification as solution nitrite after vanadium(III) reduction and
1NitroMed, Inc., Bedford, MA 01730, USA.
Free Radical Biology & Medicine
|September 19, 1998
Summary
A new method quantifies S-nitrosothiols, potential nitric oxide surrogates, by measuring their mercury-displaceable nitrogen monoxide. This sensitive technique accurately detects these compounds in biological samples.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Physiology
Background:
- S-nitrosothiols (thionitrites) are increasingly recognized as natural nitric oxide (NO) surrogates.
- They play crucial roles as intermediates in nitrogen monoxide metabolism.
- Quantifying S-nitrosothiols is vital for understanding NO-related biological processes.
Purpose of the Study:
- To develop and validate a facile, sensitive, and selective micromethod for quantifying S-nitrosothiols.
- To measure the mercury-displaceable nitrogen monoxide content of S-nitrosothiols.
- To enable detection of S-nitrosothiols in complex biological matrices.
Main Methods:
- S-nitrosothiols were pretreated with mercuric chloride to release nitrogen monoxide (NO).
- Released NO was converted to nitrite, then reduced back to NO using vanadium(III).
- NO was detected via gas-phase chemiluminescence using a commercial nitric oxide analyzer.
Main Results:
- A linear detector response was observed for S-nitrosothiol-bound NO over a wide concentration range (16.3–3500 pmol).
- The method demonstrated high selectivity for nitrite over nitrate (96%) and minimal interference from other nitrosated compounds.
- Quantitative recovery of diverse S-nitrosothiols was achieved from biological samples like plasma, surpassing the sensitivity of the Saville method.
Conclusions:
- The developed method provides a sensitive, selective, and facile approach for quantifying S-nitrosothiols.
- This technique accurately measures S-nitrosothiol-bound nitrogen monoxide in complex biological samples.
- It offers a valuable tool for advancing research into nitric oxide metabolism and related physiological functions.
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