Electron paramagnetic resonance for quantitation of nitric oxide in aqueous solutions.

نویسندگان

  • Sujatha Venkataraman
  • Sean M Martin
  • Garry R Buettner
چکیده

Nitric oxide ('NO) has many complex and diverse biological functions. 1-3 For example, it functions as an endothelium-derived relaxing factor (EDRF), a vascular antioxidant, and as a messenger molecule in the cardiovascular and immune systems. Nitric oxide also plays important roles in the biochemical aspects of a plethora of disorders. A molecule of such significance needs reliable methods for its detection and quantitation so that detailed mechanistic studies are possible. Because "NO is a reactive free radical and oxidizes rapidly to nitrite and nitrate, the quantitation of "NO in an aqueous solution is challenging. There are a number of methods for the detection of nitric oxide, 4-8 but due to lack of specificity and sensitivity, only a few are able to provide actual absolute quantitation of "NO. 9-11 The choice of the method depends on the objective of the analysis: whether it is qualitative or quantitative. Of the methods proposed so far, electron paramagnetic resonance (EPR) appears to be very useful and reliable. EPR has been used extensively to unravel the role of "NO in biological systems. 12A3 Despite "NO being a paramagnetic compound, it cannot be detected directly using EPR. However, diamagnetic compounds that form stable paramagnetic adducts with "NO can be used to detect "NO by EPR. The high affinity of "NO for certain classes of Fe 2+ complexes plays an

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عنوان ژورنال:
  • Methods in enzymology

دوره 359  شماره 

صفحات  -

تاریخ انتشار 2002