Gudelsky G A, Meltzer H Y
Neuroendocrinology. 1984 Jan;38(1):51-5. doi: 10.1159/000123865.
The synthesis and release of dopamine within tuberoinfundibular neurons were studied in rats treated with reserpine and/or pargyline. The effect of reserpine to elevate the serum concentration of prolactin was accompanied by a 70-80% reduction in the concentration of dopamine in pituitary stalk plasma. When rats were given pargyline (75 mg/kg) prior to the administration of reserpine (2.5 mg/kg), the reserpine-induced alterations in serum prolactin and stalk plasma dopamine concentrations were completely prevented. Pargyline treatment alone resulted in a significant elevation of the concentration of dopamine in pituitary stalk plasma and a reduction in the serum concentration of prolactin. The effects of reserpine and pargyline on the synthesis of dopamine in the median eminence were found to be the opposite of their effects on the release of dopamine. Dopamine synthesis (as estimated by the accumulation of dihydroxyphenylalanine after inhibition of decarboxylase activity) was increased after reserpine and decreased after pargyline administration. Thus, these data serve to illustrate the point that, under certain conditions, the release of dopamine from tuberoinfundibular neurons can be dissociated from its rate of synthesis. More importantly, it appears the release of dopamine from these neurons is dependent upon intact dopamine storage function and monoamine oxidase activity, in addition to continued catecholamine synthesis.
在接受利血平和/或优降宁治疗的大鼠中，研究了结节漏斗神经元内多巴胺的合成与释放。利血平使血清催乳素浓度升高的同时，垂体柄血浆中多巴胺浓度降低了70 - 80%。当大鼠在给予利血平（2.5毫克/千克）之前先给予优降宁（75毫克/千克）时，利血平引起的血清催乳素和垂体柄血浆多巴胺浓度的变化被完全阻止。单独使用优降宁治疗导致垂体柄血浆中多巴胺浓度显著升高，血清催乳素浓度降低。发现利血平和优降宁对正中隆起多巴胺合成的影响与其对多巴胺释放的影响相反。利血平给药后多巴胺合成（通过抑制脱羧酶活性后二羟基苯丙氨酸的积累来估计）增加，优降宁给药后减少。因此，这些数据有助于说明在某些情况下，结节漏斗神经元中多巴胺的释放可以与其合成速率分离。更重要的是，除了持续的儿茶酚胺合成外，这些神经元中多巴胺的释放似乎还依赖于完整的多巴胺储存功能和单胺氧化酶活性。
