title: Effect of dietary control on plasma nitrate level and estimation of basal systemic nitric oxide production rate in humans.
abstract: It is of great interest and value to evaluate the systemic nitric oxide (NO) production rate in humans under various conditions. However, the currently available estimation methods are troublesome and time-consuming. We thus aimed at developing a simple method to estimate the basal systemic NO production rate in humans based on a steady-state analysis, i.e., a balance between the systemic NO production rate and the total nitrate elimination rate. Plasma nitrate concentrations of young healthy volunteers (n = 7 in group 1: n = 9 in group 2) were measured for 2 days. In group 1, all subjects had the same meals for 7 days prior to the plasma nitrate measurement. In group 2, all subjects were allowed free diets. The plasma nitrate concentrations were highly influenced by dietary nitrite/nitrate intake in both groups and reached the steady-state levels after 14-h fasting. Accordingly, the basal systemic NO production rates were estimated from the plasma nitrate concentrations after 14-h fasting (group 1, 630 +/- 37 nmol min(-1) = 0.78 +/- 0.03 micromol kg(-1) h(-1); group 2, 597 +/- 45 nmol min(-1) = 0.66 +/- 0.05 micromol kg(-1) h(-1), P = not significant vs group 1). These estimated values were comparable to the values obtained by other methods. In conclusion, the present estimation method with 14-h fasting using a single-compartment analysis was found to be a simple approach to quantitative evaluation and intra- and interindividual comparisons of the basal systemic NO production rates in humans.
authors.affiliation: Department of Medical Engineering, Kawasaki Medical School, Kurashiki, Okayama, Japan. mochi@me.kawasaki-m.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Mochizuki
authors.forename: E
authors.initials: E
authors.lastname: Toyota
authors.forename: O
authors.initials: O
authors.lastname: Hiramatsu
authors.forename: T
authors.initials: T
authors.lastname: Kajita
authors.forename: F
authors.initials: F
authors.lastname: Shigeto
authors.forename: M
authors.initials: M
authors.lastname: Takemoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Kawahara
authors.forename: F
authors.initials: F
authors.lastname: Kajiya
mesh_terms: D000328:Adult; D001835:Body Weight; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D009566:Nitrates / Q000097:blood* / Q000652:urine; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D013997:Time Factors
chemical_list: D009566:Nitrates; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase