%0 Journal Article
%T Comparison of two different applications of the Griess method for nitric oxide measurement
%A Aysegul A. Yucel
%A Sebnem Gulen
%A Sibel Dincer
%A Ahmet E. Yucel
%J Journal of Experimental and Integrative Medicine
%D 2012
%I GESDAV
%X Objective: Nitric oxide (NO) is produced by various cells in response to mitogenic and inflammatory stimuli. This molecule plays important roles in the transmission of cellular signals, and in defense against pathogens by oxidative toxicity. In biological fluids, NO is rapidly converted to nitrite and nitrate. Therefore, the best index of total NO production is the sum of nitrite and nitrate. The most widely accepted classical method for measuring NO is the Griess method. Widely used commercial colorimetric kits involving the Griess method are very costly. In this study, we aimed to compare two different applications of Griess method for NO measurement. Methods: We tested two identical sets of 155 human plasma samples for NO with two different applications of the Griess method. These applications involved different deproteinization and nitrate-nitrite conversion methods. The first application was a commercial (Cayman Chemical) NO colorimetric assay with deproteinization via ultrafiltration and nitrate-nitrite conversion using NADPH-dependent nitrate reductase, and the second one was an in-house application involving sulphanilamide and N-(1-naphthyl) ethylendiamine dihydrochloride compounds with NaOH and ZnSO4 deproteinization and VaCl3 was used for nitrate-nitrite conversion. Results: The results with the se two different Griess applications were statistically correlated (r=0.954, p<0.001). The in-house method gave higher NO levels due to possible matrix-related interference; however, a regression formula was derived to convert the results of the in-house method (x) to that of commercial colorimetric assay (y): y = 1.38 + 0.388x. Conclusion: The cost of the in-house Griess method used in this study was almost one-third of the commercial assay. Use of this in-house method and the accompanying regression formula is a highly accurate and economical method for measuring NO with the Griess method. [J Exp Integr Med 2012; 2(2.000): 167-171]
%K Griess
%K NaOH
%K Nitrate reductase
%K Nitric oxide
%K Ultrafyltration
%K VaCl3
%K ZnSO4
%U http://www.scopemed.org/mnstemps/4/4-1311255653.pdf