Gubitz A K, Widdowson L, Kurokawa M, Kirkpatrick K A, Richardson P J
Department of Pharmacology, University of Cambridge, Cambridge, England.
J Neurochem. 1996 Jul;67(1):374-81. doi: 10.1046/j.1471-4159.1996.67010374.x.
Many Gs-linked receptors have been reported to use multiple signalling pathways in transfected cels but few in their normal cell environment. We show that the adenosine A2a receptor uses two signalling pathways to increase the release of acetylcholine from striatal nerve terminals. One pathway involves activation of Gs, adenylyl acylase, protein kinase A, and P-type calcium channels; the other is mediated by a cholera toxin-insensitive G protein, protein kinase C, and N-type calcium channels. The effects of these two pathways are not additive, the second pathway being inhibited by the first; but they are equally sensitive to the A2a receptor antagonist KF17837. This demonstrates that the A2a receptor activates two signalling systems in striatal cholinergic neurons.
据报道，许多与G蛋白偶联的受体在转染细胞中可使用多种信号通路，但在其正常细胞环境中却很少见。我们发现，腺苷A2a受体利用两种信号通路来增加纹状体神经末梢乙酰胆碱的释放。一种通路涉及Gs、腺苷酸环化酶、蛋白激酶A和P型钙通道的激活；另一种则由对霍乱毒素不敏感的G蛋白、蛋白激酶C和N型钙通道介导。这两种通路的作用并非相加，第二条通路会被第一条通路抑制；但它们对A2a受体拮抗剂KF17837同样敏感。这表明A2a受体在纹状体胆碱能神经元中激活了两种信号系统。
