Bai D, Sattelle D B
AFRC Laboratory of Molecular Signalling, Department of Zoology, University of Cambridge, UK.
Neurosci Lett. 1994 Jul 4;175(1-2):161-5. doi: 10.1016/0304-3940(94)91104-5.
Muscarinic acetylcholine receptors (mAChRs) on the cell body of the fast coxal depressor motor neurone (Df) in the metathoracic ganglion of the cockroach Periplaneta americana were investigated using electrophysiological methods. Muscarinic agonists, arecoline and oxotremorine, induced dose-dependent depolarizations on motor neurone Df. McN-A-343, a vertebrate mAChR M1 subtype-selective agonist, failed to induce any responses when tested on the same neurone at concentrations of up to 1.0 x 10(-4) M. The order of effectiveness of a series of muscarinic antagonists on the mAChRs of motor neurone Df is as follows: scopolamine > atropine > pirenzepine. 4-DAMP (1.0 x 10(-5) M) had only a weak blocking effect and AF-DX 116 (1.0 x 10(-5) M) was completely inactive. The pharmacological profile of muscarinic responses on motor neurone Df reveals a novel type of insect mAChR.
利用电生理方法，对美洲大蠊后胸神经节中快速髋部降压运动神经元（Df）细胞体上的毒蕈碱型乙酰胆碱受体（mAChRs）进行了研究。毒蕈碱激动剂槟榔碱和氧化震颤素可在运动神经元Df上诱导剂量依赖性去极化。脊椎动物mAChR M1亚型选择性激动剂McN-A-343，在浓度高达1.0×10⁻⁴ M时对同一神经元进行测试，未能诱导任何反应。一系列毒蕈碱拮抗剂对运动神经元Df的mAChRs的有效性顺序如下：东莨菪碱＞阿托品＞哌仑西平。4-DAMP（1.0×10⁻⁵ M）仅有微弱的阻断作用，而AF-DX 116（1.0×10⁻⁵ M）完全无活性。运动神经元Df上毒蕈碱反应的药理学特征揭示了一种新型的昆虫mAChR。
