Specific subtypes of nicotinic cholinergic receptors involved in sympathetic and parasympathetic cardiovascular responses
Specific subtypes of nicotinic cholinergic receptors involved in sympathetic and parasympathetic cardiovascular responses
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DOI：
10.1016/j.neulet.2009.06.081
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发表时间：
2009-09-18
影响因子：
2.5
通讯作者：
Freeling, Jessica
中科院分区：
文献类型：
--
作者：
Li, Yi-Fan;LaCroix, Carly;Freeling, Jessica
不同亚型的烟碱能受体在自主神经节中表达。这些受体在自主神经节传递到不同靶器官中的不同功能作用仍有待阐明。在这项研究中，我们测试了尿素麻醉小鼠对尼古丁激动剂和拮抗剂的交感和副交感心血管反应。静脉注射一种尼古丁激动剂1,1-二甲基-4-苯基哌嗪碘化物，可引起短暂但明显的心率下降，随后心率和动脉血压显著升高。心动过缓反应被阿托品阻断，而加压反应被吡嗪阻断，证实这些反应分别是副交感神经和交感神经活动。交感神经反应被选择性α - 7烟碱胆碱能受体（nAchR）拮抗剂枸橼酸甲基莱卡乌碱阻断。副交感神经反应被选择性α 4 β 2 nAchR拮抗剂氢溴二氢- β -红血碱阻断。此外，注射选择性α 4 β 2 nAchR激动剂草酸RJR2403可诱导明显的副交感神经反应和较小的交感神经反应。总的来说，这些数据表明α 4 β 2 nAchRs的激活引发副交感心血管反应，a7 nAchRs的激活引发交感心血管反应。这些数据表明，神经节水平的特定亚型尼古丁受体可能在介导交感或副交感神经激活中发挥不同的作用。2009爱思唯尔爱尔兰有限公司版权所有。
Various subtypes of nicotinic cholinergic receptors are expressed in autonomic ganglia. The distinct functional roles of these receptors in autonomic ganglionic transmission to different target organs remain to be elucidated. In this study, we tested the sympathetic and parasympathetic cardiovascular responses to nicotinic agonist and antagonists in urethane-anesthetized mice. Intravenous injection with a nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium iodide, induced a brief but pronounced decrease in heart rate, followed by significant increases in heart rate and arterial blood pressure. The bradycardic response was blocked by atropine whereas the pressor response was blocked by prazosine, confirming those responses were parasympathetic and sympathetic activities, respectively. The sympathetic response was blocked by methyllycaconitine citrate, a selective alpha 7 nicotinic cholinergic receptor (nAchR) antagonist. The parasympathetic response was blocked by a selective alpha 4 beta 2 nAchR antagonist, dihydro-beta-erythroidine hydrobromide. Moreover, injection with a selective alpha 4 beta 2 nAchR agonist, RJR2403 oxalate, induced a pronounced parasympathetic response with a smaller sympathetic response. Collectively, these data show that activations of alpha 4 beta 2 nAchRs elicits a parasympathetic cardiovascular response and activation of a7 nAchRs elicits a sympathetic cardiovascular response. These data suggest that specific subtypes of nicotinic receptors at the level of the ganglia may play distinct roles in mediating sympathetic or parasympathetic activation. (C) 2009 Elsevier Ireland Ltd. All rights reserved.