Warenycia M W, McKenzie G M
Department of Pharmacology, University of Alberta, Edmonton, Canada.
Neuropharmacology. 1988 Dec;27(12):1309-12. doi: 10.1016/0028-3908(88)90035-4.
In order to understand differences between studies maintaining that dopamine actions are significantly reduced as a result of chloral hydrate anaesthesia or not affected to any appreciable extent, striatal neuronal responses to the indirect dopamine agonist, dexamphetamine, were examined in rats anaesthetized with either chloral hydrate (400 mg/kg) or urethane (1.5 g/kg). Striatal neuronal activity was markedly depressed by chloral hydrate and urethane. However, striatal neurons still responded to 2.5 mg/kg dexamphetamine with marked excitation. These results indirectly support earlier iontophoretic studies on the excitatory action of dopamine on striatal neurons in chloral hydrate-anaesthetized animals. Furthermore, the ability of dexamphetamine, primarily an indirect dopamine agonist, to excite striatal neurons in these anaesthetized animals suggests that stimulation of both D1 and D2 receptors is not abolished by anaesthesia.
为了了解不同研究之间的差异，这些研究有的认为水合氯醛麻醉会导致多巴胺作用显著降低，有的则认为其在任何显著程度上均未受影响，我们在用400mg/kg水合氯醛或1.5g/kg乌拉坦麻醉的大鼠中，检测了纹状体神经元对间接多巴胺激动剂右旋苯丙胺的反应。水合氯醛和乌拉坦均使纹状体神经元活动显著降低。然而，纹状体神经元对2.5mg/kg右旋苯丙胺仍有明显兴奋反应。这些结果间接支持了早期关于多巴胺对水合氯醛麻醉动物纹状体神经元兴奋作用的离子电泳研究。此外，主要作为间接多巴胺激动剂的右旋苯丙胺在这些麻醉动物中激发纹状体神经元的能力表明，麻醉并未消除对D1和D2受体的刺激。
