Affordable Access

Degradation of uric acid during autocatalytic oxidation of oxyhemoglobin induced by sodium nitrite.

Authors
Type
Published Article
Journal
Free Radical Biology and Medicine
0891-5849
Publisher
Elsevier
Publication Date
Volume
11
Issue
4
Pages
373–377
Identifiers
PMID: 1797624
Source
Medline

Abstract

The oxidation of oxyhemoglobin produced by sodium nitrite occurs in two stages: 1) an initial slow phase followed by 2) a rapid autocatalytic phase that carries the reaction to completion. The length of the slow phase is extended when uric acid is added to the reaction mixture. As the concentration of uric acid increases, the length of the slow phase increases until a concentration is reached at which the rate of methemoglobin formation is nearly linear until the reaction is complete. Further increases in the concentration of uric acid do not affect the rate of the reaction in the slow phase. At low concentrations of uric acid, where an autocatalytic phase is reached, uric acid is degraded during the reaction. At concentrations of uric acid that keep the reaction in the linear phase, the uric acid is not degraded. It is concluded that uric acid may protect oxyhemoglobin by reacting with HbO2H to yield [HbOH]+ and the urate radical. The urate radical may react with a second molecule of HbO2H and become oxidized. At higher concentrations, the radical may undergo electron transfer with oxyhemoglobin to regenerate the uric acid and form methemoglobin.

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments