Lookingland K J, Moore K E
Brain Res. 1984 Dec 3;323(1):83-91. doi: 10.1016/0006-8993(84)90267-1.
The activity of incertohypothalamic, tuberoinfundibular, mesolimbic and nigrostriatal dopamine (DA) neurons was estimated by measuring the rate of turnover of DA (decline of DA after alpha-methyltyrosine) in brain regions containing the cell bodies and terminals of these neurons. Estradiol benzoate (25 micrograms/kg/day X 3; s.c.), markedly increased the concentration of prolactin in plasma and increased the rate of turnover of DA in median eminence, but failed to alter DA neuronal activity in the striatum or nucleus accumbens. An intracerebroventricular injection of prolactin (10 micrograms/rat, 12 h) mimicked the effect of estradiol on the turnover of DA in the median an eminence. Within the incertohypothalamic DA system, both estradiol and prolactin increased DA turnover in the dorsomedial nucleus but decreased DA turnover in the rostral periventricular, medial preoptic and preoptico-suprachiasmatic nuclei. Hypophysectomy decreased the tonic activity of tuberoinfundibular DA neurons, but failed to alter the activity of incertohypothalamic DA neurons. The stimulatory effects of estrogen on DA turnover in the median eminence and dorsomedial nucleus, and the inhibitory effects of this hormone on rostral hypothalamus DA neurons were blocked by hypophysectomy. Taken together these results suggest that estradiol induced changes in intact male rats are mediated by prolactin. Estradiol increased incertohypothalamic DA neuronal activity in the medial preoptic and preoptic-suprachiasmatic nuclei of hypophysectomized rats suggesting that in the absence of circulating prolactin, estradiol has a direct stimulatory effect on incertohypothalamic DA neurons in the rostral, periventricular hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)
通过测量含这些神经元胞体和终末的脑区中多巴胺（DA）的更新率（α-甲基酪氨酸处理后DA的下降）来评估未定带下丘脑、结节漏斗、中脑边缘和黑质纹状体DA神经元的活性。苯甲酸雌二醇（25微克/千克/天×3；皮下注射）显著增加血浆中催乳素的浓度，并增加正中隆起处DA的更新率，但未能改变纹状体或伏隔核中DA神经元的活性。脑室内注射催乳素（10微克/只大鼠，12小时）模拟了雌二醇对正中隆起处DA更新的影响。在未定带下丘脑DA系统内，雌二醇和催乳素均增加背内侧核中DA的更新，但降低室周前部、内侧视前和视前-视交叉上核中DA的更新。垂体切除降低了结节漏斗DA神经元的紧张性活动，但未能改变未定带下丘脑DA神经元的活性。垂体切除阻断了雌激素对正中隆起和背内侧核中DA更新的刺激作用，以及该激素对下丘脑前部DA神经元的抑制作用。综合这些结果表明，雌二醇在完整雄性大鼠中诱导的变化是由催乳素介导的。雌二醇增加了垂体切除大鼠内侧视前和视前-视交叉上核中未定带下丘脑DA神经元的活性，这表明在缺乏循环催乳素的情况下，雌二醇对室周下丘脑前部的未定带下丘脑DA神经元有直接的刺激作用。（摘要截短于250字）
