Search results for "choline"
showing 10 items of 1138 documents
The nicotinic acetylcholine receptor agonist ABT-594 increases FGF-2 expression in various rat brain regions
2000
The present experiments were designed to extend previous work showing that acute intermittent (-)nicotine treatment upregulates the level of fibroblast growth factor-2 (FGF2) mRNA in several rat brain regions, by the use of the nicotinic acetylcholine receptor (nAChR) agonist ABT-594 with preferential selectivity for the alpha4beta2 nAChR subtype. ABT594 treatment led to a well-defined temporal and regional upregulation of FGF-2 mRNA. A double labelling analysis showed that the up-regulation of FGF-2 mRNA involves both neuronal and non-neuronal cells. The effects of ABT-594 on FGF-2 expression were antagonized by the preferential alpha4beta2 antagonist dihydrobetaerythroidine (DHbetaE), but…
Postnatal alterations of the inhibitory synaptic responses recorded from cortical pyramidal neurons in the Lis1/sLis1 mutant mouse
2006
Mutations in the mouse Lis1 gene produce severe alterations in the developing cortex. We have examined some electrophysiological responses of cortical pyramidal neurons during the early postnatal development of Lis/sLis1 mutant mice. In P7 and P30 Lis1/sLis1 neurons we detected a lower frequency and slower decay phase of mIPSCs, and at P30 the mIPSCs amplitude and the action potential duration were reduced. Zolpidem (an agonist of GABAA receptors containing the alpha1 subunit) neither modified the amplitude nor the decay time of mIPSCs at P7 in Lis1/sLis1 neurons, whereas it increased the decay time at P30. The levels of GABAA receptor alpha1 subunit mRNA were reduced in the Lis1/sLis1 brai…
α7 Nicotinic acetylcholine receptors and modulation of gabaergic synaptic transmission in the hippocampus
2000
The present report provides new findings regarding modulation of gamma-aminobutyric acid (GABA) transmission by alpha7 nicotinic receptor activity in CA1 interneurons of rat hippocampal slices. Recordings were obtained from tight-seal cell-attached patches of the CA1 interneurons, and agonists were delivered to the neurons via a modified U-tube. Application for 6 s of the alpha7 nicotinic receptor-selective agonist choline (or =1 mM) to all CA1 interneurons tested triggered action potentials that were detected as fast current transients. The activity triggered by choline terminated well before the end of the agonist pulse, was blocked by the alpha7 nicotinic receptor antagonist methyllycaco…
Characterization of sensory neurotransmission and its inhibition via alpha 2B-adrenoceptors and via non-alpha 2-receptors in rabbit iris.
1993
To find out whether, and which type of, adrenoceptors mediate prejunctional inhibition of sensory neurotransmitter release from trigeminal fibres, the modulation of twitch response to electrical field stimulation on rabbit isolated iris was investigated. Evoked iris sphincter contractions consisted of a minor fast cholinergic and a large slow component. The latter was unaffected by atropine and guanethidine, hence nonadrenergic noncholinergic in nature (NANC), but nearly completely abolished by capsaicin pretreatment and by the neurokinin receptor antagonist spantide. The response was probably not mediated by NK2 receptors as SR 48,968, an NK2 selective nonpeptide antagonist, failed to redu…
Galantamine is an allosterically potentiating ligand of neuronal nicotinic but not of muscarinic acetylcholine receptors.
2003
Galantamine (Reminyl), an approved treatment for Alzheimer's disease (AD), is a potent allosteric potentiating ligand (APL) of human alpha 3 beta 4, alpha 4 beta 2, and alpha 6 beta 4 nicotinic receptors (nAChRs), and of the chicken/mouse chimeric alpha 7/5-hydroxytryptamine3 receptor, as was shown by whole-cell patch-clamp studies of human embryonic kidney-293 cells stably expressing a single nAChR subtype. Galantamine potentiates agonist responses of the four nAChR subtypes studied in the same window of concentrations (i.e., 0.1-1 microM), which correlates with the cerebrospinal fluid concentration of the drug at the recommended daily dosage of 16 to 24 mg. At concentrations10 microM, gal…
β2 long-acting and anticholinergic drugs control TGF-β1-mediated neutrophilic inflammation in COPD
2012
AbstractWe quantified TGF-β1 and acetylcholine (ACh) concentrations in induced sputum supernatants (ISSs) from 18 healthy controls (HC), 22 healthy smokers (HS) and 21 COPDs. ISSs from HC, HS and COPD as well as rhTGF-β1 were also tested in neutrophil adhesion and in mAChR2, mAChR3 and ChAT expression experiments in human bronchial epithelial cells (16-HBE). Finally, we evaluated the effects of Olodaterol (a novel inhaled β2-adrenoceptor agonist) and Tiotropium Spiriva®, alone or in combination, on neutrophil adhesion and mAChRs and ChAT expression in stimulated 16-HBE. The results showed that 1) TGF-β1 and ACh concentrations are increased in ISSs from COPD in comparison to HC and HS, and T…
Monolayers of dipalmitoylphosphatidylcholine at the oil-water interface
1995
Abstract Monolayers of dipalmitoylphosphatidylcholine at the interfaces waterbicylohexyl, waterdodecane and waterhexadecane were studied by fluorescence microscopy and thermodynamic measurements. The experiments show that the oil also partitions in the liquid condensed (LC) monolayer phase with concentration depending on the type of oil and the lateral pressure. In contrast to monolayers of dipalmitoylphosphatidylethanolamine the larger molecular area per head group enables oil partitioning in the LC phase even if there is a mismatch between the aliphatic tails of liquid and alkane.
Airways Hyperresponsiveness and the Effects of Lung Inflation
2001
Lung inflation has a beneficial effect on the airways of healthy subjects. It acts as a bronchoprotector, that is to prevent bronchoconstriction, and as a bronchodilator, in that it reverses bronchial obstruction. The bronchoprotective effect of deep inspiration is more potent than the bronchodilatory one, and the two phenomena appear to advocte different mechanisms. Asthmatics and rhinitics with airways hyperresponsiveness show an impairment in bronchoprotection induced by deep breaths, whereas the bronchodilatory effect, although reduced, is still effective. The lack of the bronchoprotective effect of deep inspiration may contribute to the development of airways hyperresponsiveness. The m…
Thermodynamic Study of Small Hydrophobic Ions at the Water–Lipid Interface
2001
Abstract The thermodynamics of binding of two small hydrophobic ions such as norharman and tryptophan to neutral and negatively charged small unilamellar vesicles was investigated at pH 7.4 using fluorescence spectroscopy. Vesicles were formed at room temperature from dimyristoyl phosphatidylcholine (DMPC) or DMPC/dimyristoylphosphatidic acid and DMPC/dimyristoylphosphatidylglycerol. The changes in fluorescence properties were used to obtain association isotherms at variable membrane surface negative charge and at different ionic strengths. The binding of both ions was found to be quantitatively enhanced as the percentage of negative phospholipid increases in the membrane. Also, a decrease …
Comparative analysis of the electrostatics of the binding of cationic proteins to vesicles: Asymmetric location of anionic phospholipids
2009
The role of electrostatics is studied in the adsorption of cationic proteins to zwitterionic phosphatidylcholine (PC) and anionic PC/phosphatidylglycerol (PG) mixed small unilamellarvesicles (SUVs). For model proteins the interaction is monitored vs. PG content at low ionic strength. The adsorption of lysozyme and myoglobin (isoelectric point, pl 7-11) is investigated in SUVs, along with changes of the fluorescence emission spectra of the cationic proteins, via their adsorption on SUVs. In the Gouy-Chapman formalism, the activity coefficient goes with the square of charge number. Deviations from the ideal model could indicate the asymmetric location of the anionic phospholipid in the bilaye…