1. A M3 MUSCARINIC RECEPTOR COUPLED TO INOSITOL PHOSPHATE FORMATION IN THE RAT COCHLEA?
- Author
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Janique Guiramand, J.F. Rumigny, Marc Lenoir, Ebrahim Mayat, Sylvain Bartolami, Max Récasens, Rémy Pujol, Bartolami, Sylvain, Neurobiologie de l'audition-plasticité synaptique, Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoires de Recherche Delalande [Rueil-Malmaison], Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Physiopathologie et thérapie des déficits sensoriels et moteurs, and Université Montpellier 2 - Sciences et Techniques (UM2)-IFR76-Institut National de la Santé et de la Recherche Médicale (INSERM)
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MESH: Inositol ,[SDV]Life Sciences [q-bio] ,Biochemistry ,chemistry.chemical_compound ,0302 clinical medicine ,MESH: Cochlea ,Muscarinic acetylcholine receptor ,Muscarinic acetylcholine receptor M4 ,Methoctramine ,MESH: Animals ,MESH: Oxotremorine ,Cells, Cultured ,0303 health sciences ,Muscarinic acetylcholine receptor M3 ,Muscarinic acetylcholine receptor M2 ,Muscarinic acetylcholine receptor M1 ,MESH: Rats, Inbred Strains ,Receptors, Muscarinic ,Cochlea ,Cell biology ,[SDV] Life Sciences [q-bio] ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,MESH: Cells, Cultured ,medicine.drug ,medicine.medical_specialty ,MESH: Rats ,Inositol Phosphates ,Lithium ,Biology ,Tritium ,03 medical and health sciences ,Internal medicine ,medicine ,Oxotremorine ,Animals ,[SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,030304 developmental biology ,Pharmacology ,MESH: Lithium ,Rats, Inbred Strains ,Pirenzepine ,MESH: Inositol Phosphates ,Rats ,MESH: Carbachol ,Endocrinology ,MESH: Receptors, Muscarinic ,MESH: Tritium ,chemistry ,Carbachol ,sense organs ,Inositol ,030217 neurology & neurosurgery - Abstract
International audience; Various neuroactive substances, including excitatory and inhibitory amino acids, biogenic amines and neuropeptides, were tested for their ability to stimulate the inositol phosphate (IPs) cascade in the presence of lithium in the rat cochlea. Among them, only the muscarinic agonists (carbachol and oxotremorine M) were able to stimulate the IPs formation in 12-day-old rat cochleas. The carbachol-elicited IPs formation was inhibited by muscarinic antagonists with the following relative order of potency: atropine greater than 4-DAMP much greater than pirenzepine greater than methoctramine = AF-DX 116. This pharmacological profile suggests that the activation of the M3 muscarinic receptor subtype is responsible for the increase in IPs synthesis in the rat cochlea. However, an interaction with a m5 receptor subtype could not be completely excluded. The unusual link of only one receptor subtype with the phosphoinositide breakdown in the cochlea, as opposed to the usual existence of several receptors coupled to this transduction system in other organs such as the brain, suggest a unique role for muscarinic agonists in the cochlea.
- Published
- 1990
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