Evans P D, Robb S
AFRC Laboratory of Molecular Signalling, Dept. of Zoology, University of Cambridge, UK.
Neurochem Res. 1993 Aug;18(8):869-74. doi: 10.1007/BF00998270.
Octopamine receptor subclasses were first proposed to explain differences in the pharmacological profiles of a range of physiological responses to octopamine obtained in the extensor-tibiae neuromuscular preparation of the locust. Thus, OCTOPAMINE1 receptors which inhibit an endogenous myogenic rhythm, increase intracellular calcium levels. Also OCTOPAMINE2 receptors which modulate neuromuscular transmission in this preparation, increase the level of adenylate cyclase activity. The current status of this classification is reviewed by examining the pharmacology of responses to octopamine in a range of preparations. It is concluded that the distinction between OCTOPAMINE1 and OCTOPAMINE2 receptor types is still valid, but that OCTOPAMINE2 receptors exhibit some tissue specific variations. Studies on a cloned Drosophila octopamine/tyramine (phentolamine) receptor are discussed and illustrate many of the difficulties presently encountered in making a definitive classification of octopamine receptors. These include the possibilities that single receptors may activate multiple second messenger systems and that different agonists may differentially couple the same receptor to different second messenger systems.
章鱼胺受体亚类最初是为了解释在蝗虫胫节伸肌神经肌肉标本中获得的一系列对章鱼胺的生理反应的药理学特性差异而提出的。因此，抑制内源性肌源性节律的章鱼胺1受体可增加细胞内钙水平。同样，在该标本中调节神经肌肉传递的章鱼胺2受体可提高腺苷酸环化酶活性水平。通过研究一系列标本中对章鱼胺反应的药理学来综述这种分类的现状。得出的结论是，章鱼胺1型和章鱼胺2型受体之间的区别仍然有效，但章鱼胺2受体表现出一些组织特异性变异。讨论了对克隆的果蝇章鱼胺/酪胺（酚妥拉明）受体的研究，这些研究说明了目前在对章鱼胺受体进行明确分类时遇到的许多困难。这些困难包括单个受体可能激活多个第二信使系统以及不同激动剂可能使同一受体与不同第二信使系统产生不同偶联的可能性。
