Journal of Pharmacological Sciences
Online ISSN : 1347-8648
Print ISSN : 1347-8613
ISSN-L : 1347-8613
Forum Minireviews
Malfunction of Vascular Control in Lifestyle-Related Diseases: Formation of Systemic Hemoglobin-Nitric Oxide Complex (HbNO) From Dietary Nitrite
Koichiro TsuchiyaYoshiharu TakiguchiMasumi OkamotoYuki IzawaYasuhisa KanematsuMasanori YoshizumiToshiaki Tamaki
Author information
JOURNAL FREE ACCESS

2004 Volume 96 Issue 4 Pages 395-400

Details
Abstract

Nitric oxide (NO) has many physiological functions. It is believed to be produced from L-arginine by nitric oxide synthase (NOS), and nitrite and nitrate are waste forms of it. By the way, nitrate and nitrite are abundant in vegetables and fruits, especially leafy vegetables and pickled vegetables. Orally-ingested nitrate is changed to nitrite by micro-organelles living in the hypopharynx area, and nitrite is expected to change to NO in the stomach due to its low pH. Indeed, some researchers reported that NO is produced in the gastric cavity, although few reports mentioned the physiological meanings of this NO formation. Therefore, we investigated whether the nitrite-derived NO can shift to the circulation and acts like NOS-derived NO does in tissues. We adopted a stable isotope of nitrite (15NO2) in order to distinguish between the endogenous nitrite and the exogenously administered one and measured nitrosyl hemoglobin (HbNO) as an index of circulating NO using electron paramagnetic resonance spectroscopy. It appeared that the oral administration of 15N-nitrite formed the Hb15NO in rat blood and decreased the blood pressure of chronic L-NAME treated rats. Our findings suggest that the intake of nitrite (or nitrate)-rich foods such as vegetables and fruits would alter the systemic HbNO dynamism, resulting in the improvement of cardiovascular diseases.

Content from these authors
© The Japanese Pharmacological Society 2004
Previous article Next article
feedback
Top