Cholinergic regulation of Na absorption by turtle colon: role of basolateral K conductance.
Cholinergic regulation of Na absorption by turtle colon: role of basolateral K conductance.
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龟结肠对钠吸收的胆碱能调节：基底外侧钾电导的作用。
DOI：
10.1152/ajpcell.1986.251.4.c563
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Dawson,DC
中科院分区：
文献类型：
--
作者：
Venglarik,CJ;Dawson,DC
毒蕈碱抑制结肠钠吸收的机制尚不清楚。在这项研究中，卡巴胆碱对主动钠转运和基底外侧钾电导的影响进行了比较，在离体龟结肠。卡巴胆碱产生的双相反应，钠运输和基底外侧钾电导。该反应包括短暂激活，随后持续抑制，并被阿托品阻断。粘膜下胆碱能神经元通过去极化剂释放内源性乙酰胆碱参与结肠转运的调节。去极化剂产生的卡巴胆碱样反应是阿托品敏感的。最后，与钙离子载体，A23187和离子霉素的实验表明，毒蕈碱反应可能介导的，至少部分地，细胞钙的变化。这些实验提供的证据表明，胆碱能神经元存在于龟结肠粘膜下层，毒蕈碱激动剂引起的变化，在基底外侧钾电导，这可能是一个重要的事件，在调节结肠钠吸收，钙第二信使系统可能参与介导的反应。
The mechanism underlying the muscarinic inhibition of colonic Na absorption is unknown. In this study the effects of carbachol on active Na transport and basolateral K conductance were compared in the isolated turtle colon. Carbachol produced a biphasic response in both Na transport and basolateral K conductance. The response consisted of a transient activation followed by a sustained inhibition and was blocked by atropine. Submucosal cholinergic neurons were implicated in the regulation of colonic transport by employing depolarizing agents to release endogenous acetylcholine. Depolarizing agents produced a carbachol-like response that was atropine-sensitive. Finally, experiments with the Ca ionophores, A23187 and ionomycin, suggested that the muscarinic response may be mediated, at least in part, by changes in cellular Ca. These experiments provide evidence that cholinergic neurons are present in the turtle colon submucosa, muscarinic agonists cause a change in basolateral K conductance that may be an important event in the regulation of colonic Na absorption, and a Ca second messenger system may be involved in mediating the response.