Lai F M, Spector S
Arch Int Pharmacodyn Ther. 1978 Aug;234(2):279-86.
Intraventricular administration of norepinephrine (NE) into pentobarbital anesthetized rats elicits a pressor or a depressor effect depending on the dose injected: after a low dose, a depressor response is seen while after a high dose, a pressor response is observed. In the animal pretreated intraventricularly with clorgyline or pyrogallol, the hypotensive effect of a low dose of NE was reversed to a hypertensive effect, while the hypertensive effect of a high dose of NE was markedly potentiated. This result suggests that brain monoamine oxidase and catechol-o-methyltransferase can metabolize centrally released NE before it leaks into the peripheral circulation.
向戊巴比妥麻醉的大鼠脑室内注射去甲肾上腺素（NE）会根据注射剂量引发升压或降压效应：低剂量注射后会出现降压反应，而高剂量注射后则会观察到升压反应。在预先经脑室内注射氯吉兰或邻苯三酚处理的动物中，低剂量NE的降压作用逆转成了升压作用，而高剂量NE的升压作用则显著增强。这一结果表明，脑内单胺氧化酶和儿茶酚-O-甲基转移酶能够在中枢释放的NE泄漏到外周循环之前将其代谢。
