Regulation of Innervation-Related Properties of Cultured Skeletal Muscle Cells by Transmitter and Co-Transmitters
Long-term interruption of the neuromuscular transmission induces marked changes in properties of skeletal muscle cells. These reversible changes were recognized for the first time in surgically denervated muscle and include the development of supersensitivity to acetylcholine1, the synthesis of extrajunctional nicotinic acetylcholine receptors (nAChRs) of the embryonic type2, depolarization of the membrane potential3 and the appearance of specific Na+- 4 and K+-channels5. Similar changes have been observed after long-term (days) pharmacological interruption of neuromuscular transmission in animals 6,7. Many of the changes in muscle brought about by pharmacological denervation are unfavourable to muscle function and/or influence the sensitivity to muscle relaxants. This has led to the assumption that changed properties of skeletal muscle induced by long-term interruption of neuromuscular transmission contribute to the paralysis syndrome observed in intensive care patients treated for prolonged periods with muscle relaxants8.
KeywordsAcetylcholine Receptor Skeletal Muscle Cell Neuromuscular Transmission C2C12 Myotubes nAChR Subunit
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