Developing skeletal muscle cells express functional muscarinic acetylcholine receptors coupled to different intracellular signaling systems
1 This study analyzed the expression of muscarinic acetylcholine receptors (mAChRs) in the rat cultured skeletal muscle cells and their coupling to G protein, phospholipase C and adenylyl cyclase (AC).2 Our results showed the presence of a homogeneous population of [H-3]methyl-quinuclidinyl benzilat...
| Autores: | , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | Brasil |
| Institución: | Universidade Federal de São Paulo (UNIFESP) |
| Repositorio: | Repositório Institucional da UNIFESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unifesp.br:11600/28475 |
| Acceso en línea: | http://dx.doi.org/10.1038/sj.bjp.0706329 http://repositorio.unifesp.br/handle/11600/28475 |
| Access Level: | acceso abierto |
| Palabra clave: | muscarinic acetylcholine receptors diacylglycerol cyclic AMP skeletal muscle G protein development |
| Sumario: | 1 This study analyzed the expression of muscarinic acetylcholine receptors (mAChRs) in the rat cultured skeletal muscle cells and their coupling to G protein, phospholipase C and adenylyl cyclase (AC).2 Our results showed the presence of a homogeneous population of [H-3]methyl-quinuclidinyl benzilate-binding sites in the membrane fraction from the rat cultured muscle (K-D = 0.4 nM, B-max = 8.9 fmol mg protein(-1)). Specific muscarinic binding sites were also detected in denervated diaphragm muscles from adult rats and in myoblasts isolated from newborn rats.3 Activation of mAChRs with carbachol induced specific [S-35]GTP gamma S binding to cultured muscle membranes and potentiated the forskolin-dependent stimulation of AC. These effects were totally inhibited by 0.1-1 mu M atropine.4 in addition, mAChRs were able to stimulate generation of diacylglycerol (DAG) in response to acetylcholine, carbachol or selective mAChR agonist oxotremorine-M.5 the carbachol-dependent increase in DAG was inhibited in a concentration-dependent manner by mAChR antagonists atropine, pirenzepine and 4-DAMP mustard.6 Finally, activation of these receptors was correlated with increased synthesis of acetylcholinesterase, via a PKC-dependent pathway.7 Taken together, these results indicate that expression of mAChRs, coupled to G protein and distinct intracellular signaling systems, is a characteristic of noninnervated skeletal muscle cells and may be responsible for trophic influences of acetylcholine during formation of the neuromuscular synapse. |
|---|