Previously we had shown that ammonia stimulates nitric oxide (NO) synthesis in astrocytes by increasing the uptake of the precursor amino acid, arginine via the heteromeric arginine/glutamine transporter y⁺LAT2. Ammonia also increases the concentration in the brain of the endogenous inhibitor of nitric oxide synthases (NOS), asymmetric dimethylarginine (ADMA), but distribution of ADMA surplus b...

In this paper, we report the status of our investigation into the feasibility of introducing a chemical agent into agricultural grade anhydrous ammonia that will render the ammonia useless for methamphetamine synthesis. Our goal is to provide a means to reduce the number, ease, and stealth that clandestine methamphetamine laboratories using the dissolving metal, or Nazi, synthetic method curren...

NH3 movement across plasma membranes has traditionally been ascribed to passive, lipid-phase diffusion. However, ammonia-specific transporters, Mep/Amt proteins, are present in primitive organisms and mammals express orthologs of Mep/Amt proteins, the Rh glycoproteins. These findings suggest that the mechanisms of NH3 movement in mammalian tissues should be reexamined. Rh C glycoprotein (Rhcg) ...

Symbiotic nitrogen recycling enables animals to thrive on nitrogen-poor diets and environments. It traditionally refers to the utilization of animal waste nitrogen by symbiotic micro-organisms to synthesize essential amino acids (EAAs), which are translocated back to the animal host. We applied metabolic modelling and complementary metabolite profiling to investigate nitrogen recycling in the s...

The assay of the hydrogenase of glucose-grown cells of Chlorella pyrenoidosa, strain 7-11-05 by means of nitrite reduction with molecular hydrogen is described. The hydrogenase of Chlorella shows maximum activity immediately after equilibration in the hydrogen atmosphere. The hydrogenase mediated reduction of nitrite to ammonia requires the presence of CO(2). However, at pH 6.4. when the reacti...

I propose a single, quick method for measuring ammonia in urine and urea in plasma and urine. An ammonia-selective electrodie is used, set up on a microcell, which allows use of small sample volumes. Ammonia is measured directly after partial conversion of ammonium ions to NH3. Urea is measured after its hydrolysis by urease. With urine, the two procedures can be carried out successively in the...

A simple, convenient, and rapid method for determining ammonia in plasma by the glutamate dehydrogenase reaction is described for the centrifugal analyzer. The measuring principle is fixed-time, with NADH as the coenzyme. ADP is added to stabilize glutamate dehydrogenase and prevent interference from endogenous plasma ADP. The reaction is linear to 400 mumol of ammonia per liter. The plasma sam...

Abstract Ammonia-mediated selective catalytic reduction (NH 3 -SCR) using Cu-exchanged chabazite zeolites as catalysts is one of the leading technologies for NO x removal from exhaust gases, with Cu II /Cu I redox cycles being basis reaction. The amount ions reduced by NO/NH can be quantified consumption during temperature-programmed experiments (NO-TPR). In this article, we show capabilities i...