Receptors acetylcholine receptors

Reaper, C.M., Fanelli, F., Buckingham, S. D Millar, N.S. and Sattelle, D.B. (1998) Antagonist profile and molecular dynamic simulation of a Drosophila melanogaster muscarinic acetylcholine receptor. Receptors Channels, 5,... 

Nicotinic acetylcholine receptor Receptor, isolated from electro-phorus electricus, was incorporated into a polymeric film formed in situ on an electronic transductor containing two terminal 1.5 cm x 1.5 cm interdigitated gold electrode. The response of the biosensor reached equilibrium within 5 s for ACh and remained stable up to 20 min. Detection limits 25 ng in a 50 pL sample (i.e., 0.5 pg/mL). [93]... 

Mode of Motion. Nicotine, anabasine, and imidocloprid affect the ganglia of the insect central nervous system, faciUtating transsynaptic conduction at low concentrations and blocking conduction at higher levels. The extent of ionisation of the nicotinoids plays an important role in both their penetration through the ionic barrier of the nerve sheath to the site of action and in their interaction with the site of action, which is befleved to be the acetylcholine receptor protein. There is a marked similarity in dimensions between acetylcholine and the nicotinium ion. 

Mode of Action. All of the insecticidal carbamates are cholinergic, and poisoned insects and mammals exhibit violent convulsions and other neuromuscular disturbances. The insecticides are strong carbamylating inhibitors of acetylcholinesterase and may also have a direct action on the acetylcholine receptors because of their pronounced stmctural resemblance to acetylcholine. The overall mechanism for carbamate interaction with acetylcholinesterase is analogous to the normal three-step hydrolysis of acetylcholine however, is much slower than with the acetylated enzyme. 

Autoantibodies are directed against nicotinic acetylcholine receptors in myasthenia gravis, resulting in receptor loss, skeletal muscle paralysis, and dysfunction (100). In addition, antibodies directed against voltage-gated Ca " channels produce similar neuromuscular dysfunction of Lambert-Eaton... 

The principal arninoglycoside toxicides are neuromuscular paralysis, ototoxicity, and nephrotoxicity. Neuromuscular paralysis is a relatively rare complication resulting from high aminoglycoside concentrations at the neuromuscular junctions following, for example, rapid bolus intravenous injection or peritoneal instillation, rather than the normal intravenous infusion. The mechanism apparentiy involves an inhibition of both the presynaptic release of acetylcholine and the acetylcholine postsynaptic receptors (51). 

Given the difficulty of obtaining three-dimensional crystals of membrane proteins, it is not surprising that the electron microscope technique is now widely used to study large membrane-bound complexes such as the acetylcholine receptor, rhodopsin, ion pumps, gap junctions, water channels and light-harvesting complexes, which crystallize in two dimensions. 

Brisson, A., Unwin, RN.T. Quaternary structure of the acetylcholine receptor. Nature 315 474-477, 1985. 

Unwin, N. Acetylcholine receptor channel imaged in the open state. Nature 373 37-43, 1995. 

Felder, C. C. (1995). Muscarinic acetylcholine receptors . Signal transduction through multiple effectors. FASEB j. 9, 619-625. 

N-Heterocycles as neuronal acetylcholine receptors in drug discovery 97JMC4169. 

Jakubic, J., and El-Fakahany, E. E. (1997). Positive coopera -tivity of acetylcholine and other agonists with allosteric ligands on muscarinic acetylcholine receptors. Mot. Pharmacol. 52 172-177. 

Positive cooperativity of acetylcholine and other agonists with allosteric ligands on muscarinic acetylcholine receptors. Mol. Pharmacol. 52 172—179. 

Paton, W. D. M., and Rang, H. P. (1965). The uptake of atropine and related drags by intestinal smooth muscle of the guinea pig in relation to acetylcholine receptors. Proc. R. Soc. Lond. [Biot.] 163 1-44. 

Jakubic, J., Bacakova, L., Lisd, V., El-Fakahany, E. E., and Tucek, S. (1996). Activation of muscarinic acetylcholine receptors via their allosteric binding sites. Proc. Natl. Acad. Sci. USA 93 8705-8709. 

Antagonists of muscarinic acetylcholine receptors had widely been used since 1860 for the treatment of Parkinson s disease, prior to the discovery of l-DOPA. They block receptors that mediate the response to striatal cholinergic interneurons. The antiparkinsonian effects of drugs like benzatropine, trihexyphenidyl and biper-iden are moderate the resting tremor may sometimes respond in a favorable manner. The adverse effects, e.g., constipation, urinary retention, and mental confusion, may be troublesome, especially in the elderly. 

Curare is a generic term for various South American arrow poisons. Curare has been used for centuries by the Indians along the Amazon and Orinoco rivers for immobilizing and paralyzing wild animals used for food. Preparations of curare are derived from Strychnos species, which contain quaternary neuromuscular alkaloids like tubocurarine. Tubocurarine is a potent antagonist at the nicotinic acetylcholine receptor. 

Muscarinic acetylcholine receptors (mAChRs) form a class of cell surface receptors that are activated upon binding of the neurotransmitter, acetylcholine. Structurally and functionally, mAChRs are prototypical members of the superfamily of G protein-coupled receptors. Following acetylcholine binding, the activated mAChRs interact with distinct classes of heterotrimeric G proteins resulting in the activation or inhibition of distinct downstream signaling cascades. 

Wess J (1996) Molecular biology of muscarinic acetylcholine receptors. CritRev Neurobiol 10 69-99... 

Caulfield MP, Birdsall NJM (1998) International Union of Pharmacology. XVII. Classification of muscarinic acetylcholine receptors. Pharmacol Rev 50 279-290... 

Wess J (2004) Muscarinic acetylcholine receptor knockout mice novel phenotypes and clinical implications. Annu Rev Pharmacol Toxicol 44 423-450... 

Lanzafame A A, Christopoulos A, Mitchelson F (2003) Cellular signaling mechanisms for muscarinic acetylcholine receptors. Recept Chann 9 241-260... 

Nicotinic receptors (nicotinic acetylcholine receptors, nACHR) exist not only in the membrane of vertebrate skeletal muscle at the synapse between nerve and muscle (muscle-type nAChR) but also at various synapses throughout the brain, mainly at presynaptic positions (neuronal-type nAChR). Whereas the muscle-type nAChR is precisely composed of two a 1-subunits, one (3 -subunit, one y -subunit and one y -subunit (adult)... 

Dajas-Bailador F, Wonnacott S (2004) Nicotinic acetylcholine receptors and the regulation of neuronal signalling. Trends Pharmacol Sci 25 317-324... 

Gotti C, Zoli M, Clementi F (2006) Brain nicotinic acetylcholine receptors native subtypes and their relevance. Trends Pharmacol Sci 27 482-491... 

Jensen AA, Frolund B, Liljefors T et al (2005) Neuronal nicotinic acetylcholine receptors structural revelations, target identifications, and therapeutic inspirations. J Med Chem 48 4705—4745... 

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