Several studies have suggested the involvement of biogenic monoaminergic neurotransmission in bipolar disorder and in the therapy for this disease. In this study, the effects of the mood-stabilizing drugs lithium, carbamazepine or valproate on the dopaminergic and adrenergic systems, particularly on D2-like and 03B2-adrenergic receptors, were studied both in cultured rat cortical neurones and in rat prefrontal ...
The behaviour of the cyclic trimeric VV complex [V3O3(μ-O)3(dmpp)3(H2O)](H2O)2, V3L3, (L = Hdmpp = 3-hydroxy-1,2-dimethyl-4-pyridinone) was studied in methanol and methanol/water solutions by using 51V and 1D- and 2D 1H NMR spectroscopy. Red crystals, isolated from a highly concentrated methanol solution of the trimeric complex, were analysed by X-ray crystallography. The solid-state structure of the compound s...
The reduced Schiff bases of salicylaldehyde [and o-vanillin (o-van)] with D,L- and L-diaminopropionic acid (DPA), designated by salDPA, and L-2,4-diaminopentanoic acid [ornithine (Orn)], designated by salOrn, as well as the VIVO2+ and VVO2+ complexes of salDPA were prepared. The compounds were characterised in the solid state and in solution. The structure of H4salDPA+Cl- was determined by X-ray diffraction. Co...
The basic catalysis of melamine with epichlorohydrin gives prepolymers that can be used in the preparation of energetic materials. In this work, sodium hydroxide and triethylamine were used as catalysts and ethyleneglycol as initiator. Different reaction conditions were tested and the characterization of the products was carried out by IR and NMR spectroscopy and MS spectrometry, hydroxyl groups content, vapour...
The uptake of the oxidation products of two oxovanadium(IV) compounds, [N,N'-ethylenebis(pyridoxylaminato)]oxovanadium(IV), VIVO(Rpyr2en), and bis-[3-hydroxy-1,2-dimethyl-4-pyridinonato]oxovanadium(IV), VIVO(dmpp)2, by human erythrocytes was studied using 51V and 1H NMR and EPR spectroscopy. VIVO(Rpyr2en) in aerobic aqueous solution is oxidized to its VV counterpart and the neutral form slowly enters the cells ...
Several sal2en-type reduced Schiff bases have been prepared from the reaction of 2 equiv. of salicylaldehyde (or derivatives) with ethylenediamine followed by reduction with NaBH4 and subsequently characterised. The water-soluble ligands (SO3-sal)2en and R(SO3-sal)2en (SO3-sal = salicylaldehyde-5-sulphonate) have been studied by pH potentiometry and 1H NMR spectroscopy and the protonation constants of R(SO3-sal...
The Schiff base N,Nprime-ethylenebis(pyridoxylideneiminato) (H2pyr2en, 1) was synthesized by reaction of pyridoxal with ethylenediamine; reduction of H2pyr2en with NaBH4 yielded the reduced Schiff base N,Nprime-ethylenebis(pyridoxylaminato) (H2Rpyr2en, 2); their crystal structures were determined by X-ray diffraction. The totally protonated forms of 1 and 2 correspond to H6L4+, and all protonation constants wer...
A simple and sensitive NMR method for quantifying excess 13C-enrichment in positions 2 and 3 of lactate by 1H NMR spectroscopy of the lactate methyl signal is described. The measurement requires neither signal calibrations nor the addition of a standard and accounts for natural abundance 13C-contributions. As a demonstration, the measurement was applied to sim3 mumol of lactate generated by erythrocyte preparat...
Magnesium is an essential element for all living systems. The quantification of free intracellular Mg(2+) concentration ([Mg(2+)](i)) is of utmost importance since changes in its basal value may be an indication of different pathologies due to abnormalities of Mg(2+) metabolism. In this work we used (31)P NMR and fluorescence spectroscopy to determine the resting [Mg(2+)](i) in bovine chromaffin cells, a neuron...
Li(+) influx by bovine chromaffin cells, obtained from bovine adrenal medulla, was studied in intact cell suspensions using (7)Li NMR spectroscopy with the shift reagent [Tm(HDOTP)](4-). The influx rate constants, k(i), were determined in the absence and in the presence of two Na(+) membrane transport inhibitors. The values obtained indicate that both voltage sensitive Na(+) channels and (Na(+)/K(+))-ATPase pla...
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