The nicotinic acetylcholine receptors of zebrafish and an evaluation of pharmacological tools used for their study

详细信息	查看全文 | 推荐本文 |

• 作者：Roger L. Papke^a ; ^{rlpapke@ufl.edu} ; Fumihito Ono^b ; Clare Stokes^a ; Jason M. Urban^b ; R. Thomas Boyd^c
• 关键词：Drug development ; Nicotine dependence ; Animal models
• 刊名：Biochemical Pharmacology
• 出版年：2012
• 期刊代码：2_00062952
• 类别：pha
• 出版时间：1 August, 2012
• 卷：84
• 期：3
• 页码：352-365
• 文件大小：2212 K

摘要

Zebrafish (Danio rerio) have been used to study multiple effects of nicotine, for example on cognition, locomotion, and stress responses, relying on the assumption that pharmacological tools will operate similarly upon molecular substrates in the fish and mammalian systems. We have cloned the zebrafish nicotinic acetylcholine receptor (nAChR) subunits and expressed key nAChR subtypes in Xenopus oocytes including neuronal (伪4尾2, 伪2尾2, 伪3尾4, and 伪7) and muscle (伪1尾1_b蓻未) nAChR. Consistent with studies of mammalian nAChR, nicotine was relatively inactive on muscle-type receptors, having both low potency and efficacy. It had high efficacy but low potency for 伪7 receptors, and the best potency and good efficacy for 伪4尾2 receptors. Cytisine, a key lead compound for the development of smoking cessation agents, is a full agonist for both mammalian 伪7 and 伪3尾4 receptors, but a full agonist only for the fish 伪7, with surprisingly low efficacy for 伪3尾4. The efficacy of cytisine for 伪4尾2 was somewhat greater than typically reported for mammalian 伪4尾2. The ganglionic blocker mecamylamine was most potent for blocking 伪3尾4 receptors, least potent for 伪7, and roughly equipotent for the muscle receptors and the 尾2-containing nAChR. However, the block of 尾2-containing receptors was slowly reversible, consistent with effective targeting of these CNS-type receptors in vivo. Three prototypical 伪7-selective agonists, choline, tropane, and 4OH-GTS-21, were tested, and these agents were observed to activate both fish 伪7 and 伪4尾2 nAChR. Our data therefore indicate that while some pharmacological tools used in zebrafish may function as expected, others will not.