Stratton K R, Baraban J M, Worley P F
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Synapse. 1988;2(6):614-8. doi: 10.1002/syn.890020606.
Protein kinase C and norepinephrine-stimulated adenylate cyclase have been linked to formation of long-term potentiation in the dentate gyrus. However, little is known about second messenger system interactions regulating synaptic transmission. In electrophysiological studies of the dentate gyrus, we observe synergistic interactions between norepinephrine and phorbol esters, activators of protein kinase C. Norepinephrine markedly potentiates the block of adenosine's inhibitory action by phorbol esters. Norepinephrine's action is mimicked by the beta-adrenoceptor agonist isoproterenol and blocked by the beta-adrenoceptor antagonists timolol and propranolol. Forskolin also mimicks norepinephrine's action. Accordingly, norepinephrine's potentiation of protein kinase C appears to be mediated by the cyclic AMP second messenger system. This mechanism may contribute to norepinephrine's facilitation of long-term potentiation in the dentate gyrus.
蛋白激酶C和去甲肾上腺素刺激的腺苷酸环化酶已与齿状回中长时程增强的形成相关联。然而，关于调节突触传递的第二信使系统相互作用却知之甚少。在对齿状回的电生理研究中，我们观察到去甲肾上腺素与佛波酯（蛋白激酶C的激活剂）之间存在协同相互作用。去甲肾上腺素显著增强佛波酯对腺苷抑制作用的阻断。β-肾上腺素能受体激动剂异丙肾上腺素可模拟去甲肾上腺素的作用，而β-肾上腺素能受体拮抗剂噻吗洛尔和普萘洛尔可阻断该作用。福斯高林也可模拟去甲肾上腺素的作用。因此，去甲肾上腺素对蛋白激酶C的增强作用似乎是由环磷酸腺苷第二信使系统介导的。这一机制可能有助于去甲肾上腺素促进齿状回中的长时程增强。
