DIAZOTIZATION REACTION OF NITRIC-OXIDE TRAPPED BY HEMOGLOBIN

The present study addresses to determine whether hemoglobin within red blood cells can be utilized as a spin-trap agent for nitric oxide. We demonstrate the diazotization method coupled with a gel filtration ch romatography, which is simply due to the separation of nitrosylhemoglo bin from nitrite, nitrate or other low molecular nitroso-compounds in biological systems and to the liberation of nitric oxide from nitrosyl heme-complexes in the acidic condition. The amount of nitric oxide ca n be estimated by the difference of absorbances at 542 nn between diaz o-compounds formed by Griess reagent and hemichrome by phosphoric acid . Our results indicate that hemoglobin in red cells as a spin-trap age nt would be useful for monitoring nitric oxide in the circulation unde r the several disease states.