Kinetic investigation on nitrite-derived nitric oxide

Abstract

In the stomach and the esophagogastric junction, nitric oxide (NO) generated by reduction of nitrite demonstrates both physiological and pathophysiological effects. In this study, generation rate and degeneration (oxidation) rate of NO were investigated in regard to the antioxidative capacity of the drinks. The NO concentration was measured using an NO-selective electrochemical sensor. ORAC, DPPH, FRAP and Folin-Ciocalteu assays were used for the evaluation of antioxidative capacity. NO generation rates were well correlated with ORAC and Folin-Ciocalteu method. Also NO degeneration rates were faster in the drinks with higher antioxidative capacity. Our results suggest that detailed investigation on the both generation and degeneration of NO are required for estimating the kinetics of nitrite-derived intragastric NO. In conclusion, ORAC and Folin-Ciocalteu assays seem to be good indices for the NO generation and degeneration capacity of antioxidant-containing drinks.