Synaptic changes in the hypothalamus of the prepuberal female rat administered estrogen.
Synaptic changes in the hypothalamus of the prepuberal female rat administered estrogen.
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给予雌激素的青春期前雌性大鼠下丘脑的突触变化。
DOI：
10.1002/aja.1001670206
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Rodriguez-Sierra,JF
中科院分区：
文献类型：
--
作者：
Clough,RW;Rodriguez-Sierra,JF
对青春期前雌性大鼠皮下注射苯甲酸雌二醇（EB）可促进阴道张开、垂体黄体生成素（LH）分泌和排卵，推测是通过神经机制实现的。本研究探讨这些影响是否与下丘脑弓状核（ARC）和视前区（POA）的突触分布的变化有关。对25日龄雌性大鼠给予EB，在第27天给予EB，然后给予孕酮，或单独给予油性溶剂;或不给予处理。第27天1600小时通过颈静脉穿刺采集血液，并通过放射免疫测定法测定血浆中的LH。立即灌注大鼠脑进行电镜检查，并解剖出ARC和POA。用磷钨酸处理这些区域的组织块，用于神经突触的选择性染色。与对照组相比，EB处理大鼠的血清LH显著升高。在给药组中，血清LH值高于1，000 ng/ml，而对照值低于50。血清LH的急性升高伴随着EB处理大鼠ARC中突触体积百分比、面积密度和数密度的急性增加。对照组的数密度为每立方毫米约8亿个观察到的突触，而在EB处理组中，每立方毫米约有18亿个突触。与对照组相比，我们发现EB处理动物的POA突触特征无差异。我们从这项研究中得出结论，雌激素通过神经机制，以加速神经内分泌过程的成熟，控制阶段性垂体LH的释放，这个成熟过程需要在ARC的突触发生。
Subcutaneous administration of estradiol benzoate (EB) to prepuberal female rats can advance vaginal opening, phasic pituitary gland luteinizing hormone (LH) secretion, and ovulation, presumably through a neural mechanism. This study investigated whether these effects are associated with changes in synaptic profiles in the arcuate nucleus of the hypothalamus (ARC) and the preoptic area (POA). Twenty‐five‐day‐old female rats were adminstered EB, EB followed by progesterone on day 27, or oil vehicle alone; or they received no treatment. Blood was collected by jugular venipuncture at 1600 hr, on day 27, and plasma was assayed for LH by radioimmunoassay. Rat brains were immediately perfused for electron microscopy, and the ARC and POA were dissected out. Tissue blocks from these areas were processed with phosphotungstic acid for selective staining of neural synapses. Serum LH was markedly elevated in the EB‐treated rats compared with controls. In the treated groups, LH values in serum were above 1,000 ng/ml, whereas the control values were less than 50. This acute rise of serum LH was accompanied by an acute increase of synaptic volume percent, area density, and numerical density in the ARC of EB‐treated rats. The numerical density of the control groups was approximately 800 million observed synapses per cubic millimeter, whereas in the EB‐treated groups, there were approximately 1.8 billion synapses per cubic millimeter. We found no differences in synaptic profiles of the POA in EB‐treated animals as compared to the controls. We conclude from this study that estrogens act through neural mechanisms to accelerate maturation of neuroendocrine processes that govern phasic pituitary gland LH release and that this maturation process entails synaptogenesis in the ARC.