Calcitonin-gene-related peptide activates the muscarinic-gated K+ current in atrial cells.
Calcitonin-gene-related peptide activates the muscarinic-gated K+ current in atrial cells.
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降钙素基因相关肽可激活心房细胞中的毒蕈碱门控 K 电流。
DOI：
10.1007/bf00550871
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Kim,D
中科院分区：
文献类型：
--
作者：
Kim,D
A high density of nerve fibers containing calcitonin-gene-related peptide (CGRP) is present in the atria. Recently CGRP was reported to open ATP-sensitive K channels in arterial smooth muscle cells. This study examines whether CGRP activates a similar K+channel in cardiac cells. In voltage-clamped whole cells loaded with GTP and ATP, CGRP reversibly evoked an inwardly rectifying K+current. To identify the K+channel that gives rise to this current, three types of K+channel (resting, ATP-sensitive and acetylcholine-activated) were examined. CGRP failed to activate or inhibit the ATP-sensitive or the resting K+channel. However, CGRP (0.1–1 μM) caused activation of single channels with kinetics similar to that of the muscarinic K+channel (35–40 pS conductance and approx. 1 ms mean open time in symmetrical 140 mM K+). In excised, inside-out (CGRP in pipette) or in outside-out (GTP in pipette) patches, the K+current was activated by perfusion with GTP or CGRP, respectively, suggesting that CGRP activated the muscarinic K+channel via GTP-binding protein. Treatment with pertussis toxin inhibited the activation of the K+channel, suggesting that CGRP receptor may be coupled to a Gior a Gotype of GTP-binding protein. Together with previous findings, these results suggest that CGRP modulates several types of ion channels to produce its cellular effects.
