A critical role for gastric xanthine oxidoreductase in the formation of S-nitrosothiols and blood pressure responses to nitrite in rats.

ABSTRACT: Nitrite and nitrate bioactivation to nitric oxide (NO) in the enterosalivary cycle of nitrate offers an enormous therapeutic potential for cardiovascular and metabolic diseases and involves xanthine oxidoreductase (XOR), an enzyme widely expressed in the gastrointestinal system. XOR has nitrite reductase activity, reducing nitrite to NO, especially under low pH conditions. Here, we hypothesized that XOR activity critically interacts with acidic gastric pH to cause the blood pressure responses to oral nitrite. To test this hypothesis, rats pretreated with the XOR inhibitor allopurinol (100 mg/kg, by gavage, or vehicle) were treated with N⍵-nitro-l-arginine methyl ester; 60 mg/kg, i.v.) to induce acute hypertension, and received sodium nitrite (1, 5, and 15 mg/kg) in the stomach or in the du

SUBMITTER: de Azevedo Medeiros CF 

PROVIDER: S-EPMC12271812 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature