TY - JOUR
T1 - Measurement of Nitric Oxide with a Solid-State-Char EPR Probe
AU - Zweier, Jay L.
AU - Samouilov, Alexandre
AU - Chzhan, Michael
PY - 1995/12
Y1 - 1995/12
N2 - Recently, highly oxygen-sensitive solid-state paramagnetic probes have been developed from glucose chars which are capable of providing measurements of very low, millitorr, oxygen concentrations in biological cells and tissues. With the increased interest and recognition of the presence and importance of the free-radical gas nitric oxide, NO·, in biology, studies were performed aimed at characterizing the effect of NO·on this probe. It was observed that NO·exerts a similar concentration-dependent broadening as does molecular oxygen, O2. In anaerobic solutions, concentrations of NO·could be detected down to 10-100 nMlevels. Measurements of NO·formation in aqueous solution were performed from a pharmacological NO·donor, which produced micromolar concentrations of NO·. This technique, however, was not sufficiently sensitive to measure physiological 1-10 nMconcentrations. Thus, the glucose-char EPR probe could be used to detect pharmacological levels of NO·but was not significantly affected by the low physiological levels which occur in normal biological tissues. These results indicate that, under normal physiological conditions, the linewidth alterations measured using the glucose-char EPR probe are solely caused by oxygen.
AB - Recently, highly oxygen-sensitive solid-state paramagnetic probes have been developed from glucose chars which are capable of providing measurements of very low, millitorr, oxygen concentrations in biological cells and tissues. With the increased interest and recognition of the presence and importance of the free-radical gas nitric oxide, NO·, in biology, studies were performed aimed at characterizing the effect of NO·on this probe. It was observed that NO·exerts a similar concentration-dependent broadening as does molecular oxygen, O2. In anaerobic solutions, concentrations of NO·could be detected down to 10-100 nMlevels. Measurements of NO·formation in aqueous solution were performed from a pharmacological NO·donor, which produced micromolar concentrations of NO·. This technique, however, was not sufficiently sensitive to measure physiological 1-10 nMconcentrations. Thus, the glucose-char EPR probe could be used to detect pharmacological levels of NO·but was not significantly affected by the low physiological levels which occur in normal biological tissues. These results indicate that, under normal physiological conditions, the linewidth alterations measured using the glucose-char EPR probe are solely caused by oxygen.
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U2 - 10.1006/jmrb.1995.9997
DO - 10.1006/jmrb.1995.9997
M3 - Article
C2 - 8542194
AN - SCOPUS:0029448015
SN - 1064-1866
VL - 109
SP - 259
EP - 263
JO - Journal of Magnetic Resonance, Series B
JF - Journal of Magnetic Resonance, Series B
IS - 3
ER -