[Recent progress of research on cardiac ion channels].
The paper summarizes the recent progress of research on the structure, function and regulation of cardiac ion channels. The primary structures of voltage-gated Na and Ca channels are homologous, with identical voltage sensors and homologous pore structure. The voltage-gated channels are modulated by sympathetic and vagal transmitters. beta-Stimulants phosphorylate various channels by activating cyclic AMP-dependent kinase, while acetylcholine antagonizes this phosphorylation. The phosphorylation inhibits the Na current by promoting inactivation, increases the L-type Ca current by increasing the channel availability, increases the delayed rectifying K current and induces Cl current. Acetylcholine induces a K current in nodal and atrial cells via a direct binding of beta gamma subunit of GTP-binding protein (GK) to the K channel.
Department of Physiology, Juntendo University School of Medicine.
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D000109:Acetylcholine / Q000378:metabolism / Q000502:physiology; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D017097:Electric Impedance; D019204:GTP-Binding Proteins / Q000378:metabolism; D008564:Membrane Potentials; D015394:Molecular Structure; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D015221:Potassium Channels / Q000378:metabolism / Q000502:physiology*; D015222:Sodium Channels / Q000378:metabolism / Q000502:physiology*
D015220:Calcium Channels; D015221:Potassium Channels; D015222:Sodium Channels; D019204:GTP-Binding Proteins; D000109:Acetylcholine