Miyamae T, Yue J L, Goshima Y, Misu Y
Department of Pharmacology, Yokohama City University School of Medicine, Japan.
Eur J Pharmacol. 1996 Apr 4;300(1-2):105-8. doi: 10.1016/0014-2999(95)00875-6.
Microinjections of L-threo-dihydroxyphenylserine (L-threo-DOPS, 0.1-3 ng), a synthetic precursor amino acid of noradrenaline, into the medial area of the nucleus tractus solitarii produced dose-dependent depressor and bradycardic responses in anesthetized rats treated with or without i.p. 3-hydroxybenzylhydrazine, a central inhibitor of L-aromatic amino acid decarboxylase. D-threo-DOPS (3 ng) produced no effect. L-Dihydroxyphenylalanine (L-DOPA) methyl ester (1 microgram), a competitive antagonist of L-DOPA, microinjected into the nucleus tractus solitarii, blocked the depressor and bradycardic responses to L-threo-DOPS itself produces vasodepressor actions without its conversion to noradrenaline, probably via a recognition site for L-DOPA in the rat nucleus tractus solitarii.
将去甲肾上腺素的合成前体氨基酸L-苏式二羟基苯丝氨酸（L-threo-DOPS，0.1 - 3纳克）微量注射到孤束核内侧区域，在腹腔注射或未注射L-芳香族氨基酸脱羧酶的中枢抑制剂3-羟基苄肼的麻醉大鼠中产生剂量依赖性的降压和心动过缓反应。D-苏式-DOPS（3纳克）无作用。将L-二羟基苯丙氨酸（L-DOPA）甲酯（1微克），一种L-DOPA的竞争性拮抗剂，微量注射到孤束核中，阻断了对L-threo-DOPS的降压和心动过缓反应，其本身在不转化为去甲肾上腺素的情况下产生血管降压作用，可能是通过大鼠孤束核中L-DOPA的识别位点实现的。
