NO is rapidly converted into the stable end products, nitrite (NO2A) and nitrate. Joint tissue from the sacrificed animals were washed with PBS (pH 7.4) and placed on ice as described [24].
Briefly a 50 ll sample was added with 100 ll of Griess reagent and the reaction mixture was incubated for about 5–10 min at room temperature and protected from light, the optical density
was measured at 540 nm in the microplate reader according to the manufacturer’s protocol. Calculations were done after generating a standard curve from sodium nitrite in the same buffer
which was used for preparation of homogenate.