Nitrate and nitrite control of anaerobic respiratory gene expression is mediated by dual two-component regulatory systems. The sensors NarX and NarQ each communicate nitrate and nitrite availability to the response regulators NarL and NarP. In the presence of nitrate, the NarX protein acts as a positive regulator ("kinase") of both NarL and NarP activity. In the presence of nitrite, the NarX pr...

We hypothesized that endotoxin would impair agonist-induced calcium (Ca2+) mobilization in rat mesangial cells, owing to the induction of nitric oxide synthase (NOS) and augmented nitric oxide (NO) synthesis. We measured basal and bradykinin-induced peak free cytosolic Ca2+ concentrations through microspectrofluorimetry with fura-2 in confluent mesangial cells, and assayed conditioned medium fo...

Previous studies of the biodegradation of nonpolar nitroaromatic compounds have suggested that microorganisms can reduce the nitro groups but cannot cleave the aromatic ring. We report here the initial steps in a pathway for complete biodegradation of 2,4-dinitrotoluene (DNT) by a Pseudomonas sp. isolated from a four-member consortium enriched with DNT. The Pseudomonas sp. degraded DNT as the s...

This study is designed to evaluate the roles of oxidative and nitrosative stress in serum and cerebrospinal fluid (CSF) of relapsing remitting multiple sclerosis (RRMS) patients. Oxidative stress markers thiobarbituric acid reactive substances (TBARS), 8-epi-PGF2α, conjugated diene and nitrosative stress markers nitrotyrosine, nitrit-nitrate were analysed in serum and CSF of 20 newly diagnosed ...

The addition of nitrite, the product of the reaction catalysed by nitrate reductase, to cell suspensions of the yeast Hansenula anomala caused a reversible inactivation of NADPH-dependent nitrate reductase activity. The haem- and Mo-dependent and Mo-dependent activities of nitrate reductase, determined with the non-physiological electron donors FMNH2 and reduced methyl viologen respectively, we...

objective(s): an increase in nitric oxide (no) production has been reported in cirrhotic cardiomyopathy and, portal hypertension. since minocycline has been shown to inhibit no overproduction, we aimed to examine its role in a rat model of ccl4-induced cirrhotic cardiovascular complications. materials and methods: portal pressure and inotropic responsiveness of isolated papillary muscles to iso...

Naphthalene dioxygenase (NDO) from Ralstonia sp. strain U2 has not been reported to oxidize nitroaromatic compounds. Here, saturation mutagenesis of NDO at position F350 of the alpha-subunit (NagAc) created variant F350T that produced 3-methyl-4-nitrocatechol from 2,6-dinitrotoluene (26DNT), that released nitrite from 23DNT sixfold faster than wild-type NDO, and that produced 3-amino-4-methyl-5...

1. The present study examined effects of arginine (Arg) and various Arg analogues on the vascular tone of rabbit and rat aortic rings, the release of nitrite from cultured bovine aortic endothelial cells and the metabolism of L-Arg in bovine and porcine endothelial cell homogenates. The respective D-enantiomers or N-alpha-benzoyl-L-arginine ethyl ester did not substitute for L-Arg. 2. In bovine...

nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing the outgrowth and production of toxin from clostridium botulinum. despite all of its desired properties, nitrite is responsible for the formation of carcinogenic n-nitrosamine. in this study, nitrite-free and low-nitrite meat curing systems were developed to eliminate or reduce nitrite f...