In leaves of spinach plants (Spinacia oleracea L.) performing CO(2) and NO(3) (-) assimilation, at the time of sudden darkening, which eliminates photosystem I-dependent nitrite reduction, only a minor temporary increase of the leaf nitrite content is observed. Because nitrate reduction does not depend on redox equivalents generated by photosystem I activity, a continuation of nitrate reduction...

Multielectron multiproton reactions play an important role in both biological systems and chemical reactions involved in energy storage and manipulation. A key strategy employed by nature in achieving such complex chemistry is the use of proton-coupled redox steps. Cytochrome c nitrite reductase (ccNiR) catalyzes the six-electron seven-proton reduction of nitrite to ammonia. While a catalytic m...

Mammalian cytochrome P450 reductase (CPR) and cytochrome P450 (CP) play important roles in organic nitrate bioactivation; however, the mechanism by which they convert organic nitrate to NO remains unknown. Questions remain regarding the initial precursor of NO that serves to link organic nitrate to the activation of soluble guanylyl cyclase (sGC). To characterize the mechanism of CPR-CP-mediate...

Nitrite was once thought to be inert in human physiology. However, research over the past few decades has established a link between nitrite and the production of nitric oxide (NO) that is potentiated under hypoxic and acidic conditions. Under this new role nitrite acts as a storage pool for bioavailable NO. The NO so produced is likely to play important roles in decreasing platelet activation,...

Nitrogen (N) isotope ratios ((15)N/(14)N) provide integrative constraints on the N inventory of the modern ocean. Anaerobic ammonium oxidation (anammox), which converts ammonium and nitrite to dinitrogen gas (N2) and nitrate, is an important fixed N sink in marine ecosystems. We studied the so far unknown N isotope effects of anammox in batch culture experiments. Anammox preferentially removes ...

BACKGROUND The recent discovery that nitrite is an intrinsic vasodilator and signaling molecule at near-physiological concentrations has raised the possibility that nitrite contributes to hypoxic vasodilation and to the bioactivity of nitroglycerin and mediates the cardiovascular protective effects of nitrate in the Mediterranean diet. However, important questions of potency, kinetics, mechanis...

Soybean (Gcine nax L. cv Williams) seeds were sown in pots containing a 1:1 perlite-vermiculite mixture and grown under greenhouse coditions. Nodules were initiated with a nitrate reductase expressing strain of Rhizobiumjaponicwn, USDA 110, or with nitrate reductase nonexpressing mutants (NR108, NR303) derived from USDA 110. Nodules initiated with either type of strain were normal in appearance...

Resting cells of Corynebacterium nephridii reduce nitrate, nitrite, and nitric oxide to nitrous oxide under anaerobic conditions. Nitrous oxide production from nitrite was optimal from pH 7.0 to 7.4. The stoichiometry of nitrous oxide production from nitrite was 99% of the theoretical-two moles of nitrite was used for each mole of nitrous oxide detected. Hydroxylamine increases gas evolution fr...

In November, 2014, the average time from submission to first decision for all original research papers submitted to Circulation Research was 13.96 days. ABSTRACT Rationale: Pre-clinical evidence demonstrates that inorganic nitrite, following its in situ conversion to nitric oxide, attenuates consequent myocardial reperfusion injury. Objective: We investigated whether intra-coronary injection of...

RATIONALE Preclinical evidence demonstrates that inorganic nitrite, after its in situ conversion to nitric oxide, attenuates consequent myocardial reperfusion injury. OBJECTIVE We investigated whether intracoronary injection of nitrite during primary percutaneous coronary intervention might improve infarct size in ST-elevated myocardial infarction. METHODS AND RESULTS Patients undergoing pr...