Measurement of Intracellular Nitric Oxide with a Quantitative Mass Spectrometry Probe Approach

Zhu Jun Zhong, Zhong Ping Yao, Zi Qi Shi, Yang Dan Liu, Li Fang Liu, Gui Zhong Xin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Nitric oxide (NO) is a molecule of physiological importance, and the function of NO depends on its concentration in biological systems, particularly in cells. Concentration-based analysis of intracellular NO can provide insight into its precise role in health and disease. However, current methods for detecting intracellular NO are still inadequate for quantitative analysis. In this study, we report a quantitative mass spectrometry probe approach to measure NO levels in cells. The probe, Amlodipine (AML), comprises a Hantzsch ester group that reacts with NO to form a pyridine, Dehydro Amlodipine (DAM). Quantification of DAM by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) allows specific measurement of intracellular NO levels. Notably, the AML/NO reaction proceeds rapidly (within 1 s), which is favorable for NO detection considering its large diffusivity and short half-life. Meanwhile, studies under simulated physiological conditions revealed that the AML response to NO is proportional and selective. The presented UPLC-MS/MS method showed high sensitivity (LLOQ = 0.24 nM) and low matrix interference (less than 15%) in DAM quantification. Furthermore, the mass spectrometry probe approach was demonstrated by enabling the measurement of endogenous and exogenous NO in cells. Hence, the quantitative UPLC-MS/MS method developed using AML as a probe is expected to be a new method for intracellular NO analysis.

Original languageEnglish
Pages (from-to)8536-8543
Number of pages8
JournalAnalytical Chemistry
Volume93
Issue number24
DOIs
Publication statusPublished - 22 Jun 2021

ASJC Scopus subject areas

  • Analytical Chemistry

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