Hollister A S, Breese G R, Mueller R A
J Pharmacol Exp Ther. 1979 Jan;208(1):37-43.
The potentiation of the stimulatory response to L-dihydroxyphenylalanine (L-dopa) in 6-hydroxydopamine-treated rats given a peripheral decarboxylase inhibitor occurred only after treatments that destroyed dopamine-containing fibers, Destruction of serotonin- or norepinephrine-containing fibers did not potentiate the action of L-dopa. Furthermore, other data indicated thatL-dopa-induced activity could not be attributed to release of serotonin or to the formation of norepinephrine. That the L-dopa must be converted to catecholamines was demonstrated by antagonism of the activity responses to L-dopa with inhibition of decarboxylases in brain. After destruction of serotonin-containing fibers with 5,7-dihydroxytryptamine, L-dopa-induced activity in 6-hydroxydopamine-treated rats was significantly reduced, as was the accumulation of dopamine formed from L-dopa. These latter data provide direct evidence that serotonergic fibers contribute to the accumulation of dopamine in brain after L-dopa administration to 6-hydroxydopamine-treated rats.
给予外周脱羧酶抑制剂的6-羟基多巴胺处理大鼠，对L-二羟基苯丙氨酸（L-多巴）刺激反应的增强仅在破坏含多巴胺纤维的处理后出现，破坏含5-羟色胺或去甲肾上腺素的纤维并未增强L-多巴的作用。此外，其他数据表明，L-多巴诱导的活性不能归因于5-羟色胺的释放或去甲肾上腺素的形成。脑内脱羧酶的抑制对L-多巴活性反应的拮抗作用证明，L-多巴必须转化为儿茶酚胺。用5,7-二羟基色胺破坏含5-羟色胺的纤维后，6-羟基多巴胺处理大鼠中L-多巴诱导的活性显著降低，由L-多巴形成的多巴胺积累也显著降低。这些最新数据提供了直接证据，表明5-羟色胺能纤维在给6-羟基多巴胺处理的大鼠施用L-多巴后，有助于脑内多巴胺的积累。
