Disease relevance of tetramethylammonium

• Changes in extracellular space (ECS) diffusion parameters in astrogliotic tissue around a unilateral cortical stab wound were determined from concentration-time profiles of tetramethylammonium (TMA(+)) using TMA(+)-selective microelectrodes [1].
• 3. Extracellular volume fraction and tortuosity were determined during normoxic conditions and in vitro ischemia by measuring the diffusion of tetramethylammonium [2].
• Paracoccus kocurii sp. nov., a tetramethylammonium-assimilating bacterium [3].
• 4. Also at 21-22 degrees neither stimulation nor anoxia generated more than minimal reductions in extracellular space [by 2.3 +/- 0.94%, as measured by the tetramethylammonium (TMA) method], and spreading depression (SD) occurred in only 1 out of 20 slices [4].
• These results indicate that isopropylamine has both ganglion stimulating and blocking properties and is similar in its action to the classical nicotinic ganglion stimulant drugs such as dimethylphenylpiperazinium iodide and tetramethylammonium [5].

High impact information on tetramethylammonium

• Moreover, expression of the Arabidopsis ALF5 cDNA in yeast confers resistance to tetramethylammonium [6].
• In isolated cardiac ventricular myocytes, the beta-adrenergically regulated Cl- current (ICl) exhibited an unusual dependence on Na+, such that replacement of extracellular Na+ with compounds such as tetramethylammonium, choline, Tris, or N-methyl-D-glucamine resulted in a reduction in current amplitude without changing the reversal potential [7].
• Epithelial cells of the gallbladder of Necturus maculosus were loaded with tetramethylammonium (Me4N+) by transient exposure of the apical (lumen-facing) surface to a solution of high Me4N+ concentration containing also the polyene antibiotic nystatin [8].
• Lowering Na+ gradient by replacing extracellular Na+ with tetramethylammonium (TMA) increased the number of activated alpha IIb beta 3 by twofold, as assessed by fibrinogen-binding assay [9].
• Changes in hepatocyte steady-state water volume were determined by changes in intracellular tetramethylammonium activity measured with tetramethylammonium-sensitive, double-barrel micro-electrodes 4 min after exposure to hyposmotic medium [10].

Chemical compound and disease context of tetramethylammonium

• DPA in whole cells of sporulated Bacillus anthracis reacted in situ during pyrolysis with tetramethylammonium hydroxide to form the dimethyl ester derivative of DPA, dimethyl-2,6-dipicolinate (mDPA) [11].
• It was established that the water-soluble toxin responsible for poisonings, following ingestion of this snail, is tetramine (the tetramethylammonium ion present as an unknown salt) [12].

Biological context of tetramethylammonium

• Changes in retinal pigment epithelial (RPE) cell volume were measured by monitoring changes in intracellular tetramethylammonium (TMA) using double-barreled K-resin microelectrodes [13].
• RESULTS: In the presence of an inside-negative membrane potential, imposing an inwardly-directed Na+-gradient versus tetramethylammonium (TMA) stimulated the initial [3H]MI uptake in BLMV and LMV [14].
• A collection of tannins extracted from various plant species was subjected to thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide [15].
• Taken together these experiments demonstrate the existence of a common binding site on MADHox for the substrate CH3NH3+, the substrate analogues (CH3)2NH2+, (CH3)3NH+, and (CH3)4N+, and the monovalent cations Cs+, Rb+, and NH4+ [16].
• Tetraethylammonium, tetramethylammonium, or Cs (10 mM) on the cytoplasmic side of the membrane caused a voltage-dependent decrease in conductance of the open channel while having no obvious effect on channel kinetics [17].

Anatomical context of tetramethylammonium

• Diffusion measurements using the tetramethylammonium method showed that the extracellular space, typically occupying 20% of brain tissue in vivo, was decreased to 10% at 30 minutes and 15% at 6 hours in both deep and superficial layers of thick slices [18].
• After expression in X. laevis oocytes, the IC(50) ratios of wild-type and D475E mutant were 1.7 (tetramethylammonium), 4.3 (TEA), 5.0 (tetrapropylammonium), 5.0 (tetrabutylammonium), and 65 (tetrapentylammonium) [19].
• In additional animals, changes in extracellular fluid pH (pHe) were measured with ion-selective microelectrodes, and extracellular fluid (ECF) volume was calculated from the diffusion profile for electrophoretically administered tetramethylammonium [20].
• 1. Identified neurones of the suboesophageal ganglia of Helix aspersa were loaded with tetramethylammonium (TMA+) [21].
• 3. The nicotinic agonists nicotine, tetramethylammonium and lobeline evoked inward currents in bovine chromaffin cells [22].

Associations of tetramethylammonium with other chemical compounds

• The rate of pH gradient dissipation was stimulated 6.3-fold by the replacement of tetramethylammonium gluconate by tetramethylammonium chloride [23].
• Ethidium fluorescence experiments demonstrated that conotoxin is formally competitive with a small cholinergic ligand, tetramethylammonium [24].
• In the presence of valinomycin, the replacement of tetramethylammonium gluconate by K gluconate increased the rate of delta pH dissipation by 11-fold, demonstrating the existence of a conductive pathway for protons [23].
• The magnetic susceptibility and single-crystal X-ray structure of the one-dimensional Heisenberg antiferromagnetic chain tetramethylammonium manganese trichloride (TMMC) have been studied under pressure as a facile route to develop structure-property relationships [25].
• The arl1 mutant was sensitive to toxic cations, including hygromycin B and other aminoglycoside antibiotics, tetramethylammonium ions, methylammonium ions and protons [26].

Gene context of tetramethylammonium

• The largest permeant ion, tetramethylammonium with a diameter of 0.55 nm, had PTMA/PNa of 0.09 [27].
• All three antibodies were raised against the same antigen, human erythrocyte AChE, a commercial product purified using the cholinesterase anionic site inhibitor, tetramethylammonium [28].
• Rat VAChT was expressed in PC12(A1237) cells, postnuclear supernatant-containing microvesicles was prepared, and the reorientation assay was conducted with unlabeled Ch and tetramethylammonium (TMA) [29].
• Control experiments with fluorescent dextran of similar molecular weight and tetramethylammonium confirmed EGF did not affect local ECS structure [30].
• ECS tortuosity lambda = (D/ADC)0.5, where D is the free diffusion coefficient and ADC is the apparent diffusion coefficient of TMA+ in the brain, increases as measured perpendicular to the axons from 1.53 +/- 0.02 (n = 6, mean +/- SEM) to 1.70 +/- 0.02 (n = 6) [31].

Analytical, diagnostic and therapeutic context of tetramethylammonium

• The real-time tetramethylammonium (TMA) method and diffusion-weighted MRI were used to measure the ECS volume fraction (alpha = ECS volume/total tissue volume) and the apparent diffusion coefficients (ADCs) of TMA (ADC(TMA)), diffusing exclusively in the ECS and of water (ADC(W)) [32].
• Changes in cell water content result in changes in intracellular TMA+ activity which are measured with intracellular ion-sensitive microelectrodes [33].
• The internal KF perfusion medium can be diluted by tetramethylammonium (TMA), Tris, or sucrose solutions with the same decrease in PNa/PK [34].
• Diffusion of fluorophore-labeled dextran (f-dex, M(r) 3,000) and tetramethylammonium (TMA(+), M(r) 74) was measured in rat brain slices (400 mum) using integrative optical imaging (IOI) and real-time iontophoresis (RTI), respectively [35].
• The authors perfused chick retina-RPE-choroid preparations with the extracellular space marker, tetramethylammonium (TMA+), and estimated its concentration ([TMA+]o) using double-barreled, ion-selective electrodes [36].

References