Search results for " acetylcholine"

PRESYNAPTIC MUSCARINIC CONTROL OF NORADRENALINE RELEASE

1980

ChemInform Abstract: Regioisomeric 3-, 4-, and 5-Aminomethylisoxazoles: Synthesis and Muscarinic Activity.

2010

Detection of Non-neuronal Acetylcholine

2016

Synthesis and in vitro evaluation of galanthamine derivatives for examination of nicotinic acetylcholine receptor system

2001

ISunmrary: The syntheses and radioactive labeling of several galanthamine derivatives, 6-O-demethyl-6-O-fluoroethylgalanthamine, 10-N-demethyl-lO-Nfluoroethylgalanthamine and N-methylgalanthaminium are reported. First ill vitro evaluations were carried out to determine their properties as allosterically potentiating ligands of nicotinic receptors. N-methylgalanthaminium was found to be a promising candidate for further investigations. The most commonly applied therapeutic approach to balance nicotinic cholinergic deficits in Alzheimer’s disease (AD) patients is the administration of acetylcholinesterase inhibitors (AChE-I) although they have been proven to be of limited therapeutic value [ …

Pre- and Postsynaptic Effects of Muscarinic Antagonists in the Isolated Guinea Pig Ileum

1986

Several compounds have been claimed to differentiate between subtypes of muscarinic receptors (2). In the experiments described in this chapter we have studied in the guinea-pig ileum whether the presynaptic muscarinic receptors of the cholinergic nerves differ from the postsynaptic muscarinic receptors of the longitudinal muscle in their affinities for several muscarinic antagonists (methylatropine; trihexyphenidyl; clozapine; DAMP). Inhibition by oxotremorine of the evoked release of acetylcholine (ACh) was used as a parameter of presynaptic activity, and the increase by oxotremorine of smooth muscle tension as a postsynaptic parameter. The affinity constants (pA2 values) of the antagonis…

Monoclonal antibodies FK1 and WF6 define two neighboring ligand binding sites on Torpedo acetylcholine receptor alpha-polypeptide.

1994

Previous studies have identified the sequence region flanking the invariant vicinal cysteinyl residues at positions 192 and 193 of the nicotinic acetylcholine receptor alpha-subunit as containing major elements of the binding site for acetylcholine and its agonists and antagonists, including antibody WF6 (Conti-Tronconi, B. M., Diethelm, B. M., Wu, X., Tang, F., Bertazzon, T., Schroder, B., Reinhardt-Maelicke, A., and Maelicke, A. (1991) Biochemistry 30, 2575-2584). Recently we have shown that the sequence region flanking lysine alpha 125 contains elements of the binding site for physostigmine and related ligands, including antibody FK1 (Schrattenholz, A., Godovac-Zimmerman, J., Schafer, H.…

<title>Spectroscopic investigation of the nicotinic acetylcholine receptor for application in medical diagnosis</title>

1998

Native vesicles containing the nicotinic acetylcholine receptor (nAChR) prepared from the electric organ of the ray Torpedo marmorata were used to obtain fluorescence signal sin dependence of different concentrations of the local anesthetics procaine. Nonlinear concentration dependent spectral changes are found using ethidium bromide as a fluorescence marker. Structural changes are found for the proteins including the nAChR in the vesicles during immobilization onto surfaces such as IR transparent germanium (GE) crystal, Ge crystal coated with silver (Ag) cluster to use the SEIRA effect and/or crystals covered with a lipid subphase. A comparison between Ge and Ge coated with Ag (Ge/Ag) clus…

Heteroreceptor-mediated modulation of noradrenaline and acetylcholine release from peripheral nerves

2006

Allosteric modulation of nicotinic acetylcholine receptors as a treatment strategy for Alzheimer's disease

2000

The basic symptoms of Alzheimer's dementia, i.e., a loss in cognitive function, are due to impaired nicotinic cholinergic neurotransmission. To compensate for this impairment by drug treatment, blockers of the acetylcholine-degrading enzyme acetylcholinesterase are applied, even though this approach obviously is prone to many side-effects, including those of muscarinic nature. We have recently described a novel class of nicotinic acetylcholine receptor ligands which, similar to the action of benzodiazepines on GABA(A) receptors, allosterically potentiate submaximal nicotinic responses. The sensitizing effect is a consequence of facilitated channel opening in the presence of allosterically p…

Atropine-resistant effects of the muscarinic agonists McN-A-343 and AHR 602 on cardiac performance and the release of noradrenaline from sympathetic …

1974

Abstract 1 The effects of 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343) and N-benzyl-3-pyrrolidyl acetate methobromide (AHR 602) on cardiac performance and noradrenaline release from terminal sympathetic fibres were measured in isolated perfused hearts of rabbits. 2 In the presence of sufficient atropine to block muscarinic receptors, high concentrations of McN-A-343 and AHR 602 caused no cardiac stimulation and there was no increase in the resting output of noradrenaline into the perfusates. 3 McN-A-343 and AHR 602 increased both the mechanical responses and the transmitter overflow evoked by electrical stimulation of the sympathetic nerves (SNS) but inhibi…