Improved detection of nitric oxide radical (NO•) production in an activated macrophage culture with a radical scavenger, car☐y PTIO, and Griess reagent

Abstract

An improved method for the detection of nitric oxide radicals (NO^•in cultures of activated macrophages was developed, involving a nitric oxide radical scavenger, 2‐(4‐car☐yphenyl)‐4, 4, 5, 5‐tetramethylimidazoline‐3‐oxide‐l‐oxyl (car☐y PTIO) and Griess reagent. A murine macrophage‐like cell line, J774.1, was activated with interferon‐γ (IFN‐γ) and bacterial lipopolysaccharide (LPS), which induced the production and secretion of NO₂ ⁻ into the culture supernatant. Addition of car☐y PTIO to the activated macrophages increased the amount of NO₂ ⁻¹ to 4‐ to 5‐fold without cell damages, probably because car☐y PTIO rapidly reacted with NO^• to form NO₂ ⁻¹ which was finally assayed by the Griess reaction.