Beleslin D B, Strbac M
Department of Pharmacology, Medical Faculty, Beograd, Yugoslavia.
Neuropharmacology. 1987 Aug;26(8):1157-65. doi: 10.1016/0028-3908(87)90262-0.
The emetic action of noradrenaline was investigated in unanesthetized cats, after it was injected into the cerebral ventricles through chronically implanted cannulae. Intracerebroventricular injection of noradrenaline produced dose-dependent and shortlasting emesis, which was abolished after ablation of the area postrema. However, copper sulphate, given orally, evoked emesis in cats with an ablated area postrema. The selective alpha-2 adrenoceptor antagonist, yohimbine, as well as the mixed alpha-1 and alpha-2 adrenoceptor blocking drugs, phentolamine, tolazoline, phenoxybenzamine and dihydroergotamine, but not the selective alpha-1 adrenoceptor antagonist, prazosin, all injected into the cerebral ventricles, attenuated or blocked the emesis evoked by intracerebroventricular injection of noradrenaline. Of the alpha-adrenoceptor antagonist, only yohimbine produced dose-dependent inhibition of the emesis induced by noradrenaline. On the contrary, selected beta-adrenoceptor blocking agents, an antimuscarinic drug, a ganglionic blocking agent, an antihistamine, dopamine antagonists and a 5-hydroxytryptamine antagonist, all injected into the cerebral ventricles, had no significant effect on the emesis induced by noradrenaline, similarly injected. The emetic response to intracerebroventricular injection of noradrenaline, as well as to intragastric administration of copper sulphate was not altered in cats pretreated with intracerebroventricular injections of alpha-methyl-p-tyrosine and bretylium. On the other hand, the emetic response to intracerebroventricular injection of noradrenaline and to intragastric administration of copper sulphate was attentuated or blocked in cats pretreated with reserpine intracerebroventricularly. Moreover, in cats pretreated with intracerebroventricular injection of 6-hydroxydopamine and hemicholinium, the emesis induced by intracerebroventricular administration of noradrenaline but not that produced by intragastric injection of copper sulphate, was depressed.(ABSTRACT TRUNCATED AT 250 WORDS)
通过长期植入的套管将去甲肾上腺素注入未麻醉猫的脑室后，对其催吐作用进行了研究。脑室内注射去甲肾上腺素会产生剂量依赖性且持续时间较短的呕吐，在最后区被切除后这种呕吐反应消失。然而，口服硫酸铜会使最后区被切除的猫引发呕吐。选择性α-2肾上腺素能受体拮抗剂育亨宾，以及混合的α-1和α-2肾上腺素能受体阻断药物酚妥拉明、妥拉唑啉、酚苄明和双氢麦角胺，但不包括选择性α-1肾上腺素能受体拮抗剂哌唑嗪，所有这些药物注入脑室后，都会减弱或阻断脑室内注射去甲肾上腺素所引发的呕吐。在α-肾上腺素能受体拮抗剂中，只有育亨宾对去甲肾上腺素诱导的呕吐产生剂量依赖性抑制。相反，选择性β-肾上腺素能受体阻断剂、抗毒蕈碱药物、神经节阻断剂、抗组胺药、多巴胺拮抗剂和5-羟色胺拮抗剂，所有这些药物注入脑室后，对同样注射的去甲肾上腺素所诱导的呕吐没有显著影响。在用α-甲基对酪氨酸和溴苄铵脑室注射预处理的猫中，对脑室内注射去甲肾上腺素以及胃内给予硫酸铜的催吐反应没有改变。另一方面，在用利血平脑室注射预处理的猫中，对脑室内注射去甲肾上腺素以及胃内给予硫酸铜的催吐反应减弱或被阻断。此外，在用6-羟基多巴胺和半胱氨酸脑室注射预处理的猫中，脑室内给予去甲肾上腺素所诱导的呕吐受到抑制，但胃内注射硫酸铜所产生的呕吐不受影响。（摘要截稿于250字）
