Demling J, Fuchs E, Baumert M, Wuttke W
Neuroendocrinology. 1985 Sep;41(3):212-8. doi: 10.1159/000124180.
The push-pull cannula technique was used to evaluate the role of the medial preoptic/anterior hypothalamic area (MPO) in regulating pituitary luteinizing hormone (LH) and prolactin release. The concentrations of the three catecholamines--dopamine, norepinephrine (NE), epinephrine (E)--and gamma-aminobutyric acid (GABA) and glutamate could be measured in 15-min fractions at which interval blood samples for LH and prolactin determination were also collected. Comparison of neurotransmitter release rates into the MPO were made between ovariectomized and ovariectomized estradiol benzoate treated rats. Release of the neurotransmitters occurred in a pulsatile manner, the release episodes for each transmitter appeared to be independent of the others. No direct correlation between neurotransmitter release episodes and blood LH or prolactin levels could be established. The release of GABA was significantly lower and that of NE and E higher in ovariectomized animals in comparison to estrogen-primed ovariectomized animals under negative feedback conditions. In the afternoon, however, when the estrogen stimulated LH and prolactin release, preoptic GABA release was low, whereas preoptic NE and particularly E release rates were high. Conspicuously high dopamine and NE release episodes were observed in estrogen-primed animals at noon, i.e., prior to the expression of the positive feedback signal. This may reflect a biochemical correlate to the so-called critical period. No consistent differences between ovariectomized and ovariectomized estradiol-17 beta benzoate treated animals were observed for preoptic glutamate release rates. The data show that preoptic GABA release rates show generally an inverse pattern to NE and E release and therefore also to blood LH and prolactin levels. No direct mathematical correlation between any of the neurotransmitter release rates and blood hormone levels could be established.
采用推挽套管技术评估内侧视前区/下丘脑前区（MPO）在调节垂体促黄体生成素（LH）和催乳素释放中的作用。可以每隔15分钟测定一次三种儿茶酚胺——多巴胺、去甲肾上腺素（NE）、肾上腺素（E）——以及γ-氨基丁酸（GABA）和谷氨酸的浓度，在此期间还采集血样用于测定LH和催乳素。比较了去卵巢大鼠和去卵巢后经苯甲酸雌二醇处理的大鼠MPO中神经递质的释放速率。神经递质以脉冲方式释放，每种递质的释放事件似乎相互独立。未能确定神经递质释放事件与血LH或催乳素水平之间的直接相关性。在负反馈条件下，与雌激素预处理的去卵巢动物相比，去卵巢动物中GABA的释放显著降低，而NE和E的释放则较高。然而，在下午，当雌激素刺激LH和催乳素释放时，视前区GABA释放较低，而视前区NE尤其是E的释放速率较高。在中午，即在正反馈信号表达之前，在雌激素预处理的动物中观察到多巴胺和NE释放事件明显增加。这可能反映了与所谓关键期相关的生化关联。去卵巢大鼠和去卵巢后经17β-苯甲酸雌二醇处理的大鼠视前区谷氨酸释放速率未观察到一致的差异。数据表明，视前区GABA释放速率通常与NE和E的释放呈相反模式，因此也与血LH和催乳素水平呈相反模式。未能确定任何神经递质释放速率与血激素水平之间的直接数学相关性。
