Estrogen receptor-alpha expression in osmosensitive elements of the lamina terminalis: regulation by hypertonicity.
Estrogen receptor-alpha expression in osmosensitive elements of the lamina terminalis: regulation by hypertonicity.
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终板渗透敏感元件中雌激素受体α的表达：高渗调节。
DOI：
10.1152/ajpregu.00136.2004
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Sladek,CeliaD
中科院分区：
文献类型：
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作者：
Somponpun,SuwitJ;Johnson,AlanKim;Beltz,Terry;Sladek,CeliaD
穹窿下器（SFO）、正中视前核（MnPO）和终板血管器（OVLT）与终板相连，在体液平衡的控制中起重要作用。这些区域的神经元表达雌激素受体（ER）-α，但ER-α神经元是否被高渗激活以及高渗是否调节ER-α表达尚不清楚。采用荧光免疫细胞化学双标记技术，检测了正常对照组和禁水组大鼠海马ER-α免疫反应（ir）和Fos-ir的表达。在对照动物中，在SFO的外周、背侧和腹侧MnPO以及OVLT的背帽中有大量ER-α阳性神经元表达。Fos阳性神经元稀疏，但在sFO，MnPO，和背帽的OVLT 48小时的水剥夺后，大量的。大部分ER-α-ir神经元Fos阳性，表明ER-α-ir神经元存在明显的共定位。为了检测脱水对ER-α表达的影响，将第三脑室（AV 3V）前部和腹侧部分周围有和无病变的动物禁水48 h。禁水后，假手术组大鼠SFO中ER-α-ir中度升高（P= 0.03），AV 3V组大鼠SFO中ER-α-ir显著升高（P< 0.05）。这可能是由两个脱水组中血浆渗透压摩尔浓度的显著增加（P< 0.001）而不是血容量的减少引起的，因为红细胞压积仅在脱水假损伤动物中显著增加。因此，这些研究暗示终板的激素敏感区域可能是性类固醇对体液稳态作用的靶点。
The subfornical organ (SFO), median preoptic nucleus (MnPO), and organum vasculosum lamina terminalis (OVLT), which are associated with the lamina terminalis, are important in the control of body fluid balance. Neurons in these regions express estrogen receptor (ER)-α, but whether the ER-α neurons are activated by hypertonicity and whether hypertonicity regulates ER-α expression are not known. Using fluorescent, double-label immunocytochemistry, we examined the expression of ER-α-immunoreactivity (ir) and Fos-ir in control and water-deprived male rats. In control animals, numerous ER-α-positive neurons were expressed in the periphery of the SFO, in both the dorsal and ventral MnPO, and in the dorsal cap of the OVLT. Fos-positive neurons were sparse in euhydrated rats but were numerous in the SFO, MnPO, and the dorsal cap of the OVLT after 48-h water deprivation. Most ER-α-ir neurons in these areas were positive for Fos, indicating a significant degree of colocalization. To examine the effect of dehydration on ER-α expression, animals with and without lesions surrounding the anterior and ventral portion of the 3rd ventricle (AV3V) were water deprived for 48 h. Water deprivation resulted in a moderate increase in ER-α-ir in the SFO of sham-lesioned rats (P= 0.03) and a dramatic elevation in AV3V-lesioned animals (P< 0.05). This was probably induced by the significant increase in plasma osmolality in both dehydrated groups (P< 0.001) rather than a decrease in blood volume, because hematocrit was significantly increased only in the dehydrated sham-lesioned animals. Thus these studies implicate the osmosensitive regions of the lamina terminalis as possible targets for sex steroid effects on body fluid homeostasis.