Effects of ovariectomy on GnRH mRNA, proGnRH and GnRH levels in the preoptic hypothalamus of the female rat.
Effects of ovariectomy on GnRH mRNA, proGnRH and GnRH levels in the preoptic hypothalamus of the female rat.
复制标题
卵巢切除对雌性大鼠视前下丘脑 GnRH mRNA、proGnRH 和 GnRH 水平的影响。
DOI：
10.1159/000125095
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发表时间：
1989
影响因子：
4.1
通讯作者：
Ronnekleiv,OK
中科院分区：
文献类型：
--
作者：
Kelly,MJ;Garrett,J;Bosch,MA;Roselli,CE;Douglass,J;Adelman,JP;Ronnekleiv,OK
本实验旨在探讨卵巢切除术对雌性大鼠下丘脑促性腺激素释放激素（GnRH）信使RNA （mRNA）、前GnRH和GnRH肽水平的影响。取完整的雌性大鼠和切除卵巢2周的雌性大鼠，于9.00 h处死，取出视前区（POA）和基底下丘脑（BH），干冰冷冻。用乙酸提取一组未发情雌性和去卵巢雌性的组织，在13000℃离心，上清在c18柱上纯化。然后用大鼠proGnRH特异性抗血清（ARK-2）对纯化的提取物进行proGnRH放射免疫检测，用El-14抗血清对GnRH进行放射免疫检测。从另一组组织中分离总细胞RNA并制备为Northern blots。与32p标记的GnRH cRNA杂交检测GnRH mRNA。第三组去势雌性大鼠灌注，切50µm振动切片。用proGnRH或GnRH抗血清对这些细胞进行免疫染色，然后用3ss标记的GnRH cRNA进行原位杂交以检测GnRH mRNA。通过组织化学染色，mRNA被共定位到POA和BH中含有proGnRH和GnRH的神经元的细胞体中。根据放射免疫测定，POA的proGnRH水平比BH高2倍，但BH的GnRH水平高6-7倍。卵巢切除术显著降低POA和BH的proGnRH水平，而BH的GnRH下降。相比之下，定量Northern blot分析显示卵巢切除术对POA和BH的mRNA水平没有影响。这些数据表明卵巢切除术对原GnRH和GnRH水平的影响是GnRH翻译、翻译后加工和/或分泌改变的结果。
Experiments were carried out to investigate the effects of ovariectomy on gonadotropin-releasing hormone (GnRH) messenger RNA (mRNA), proGnRH and GnRH peptide levels in the hypothalamus of female rats. Intact proestrous female rats and female rats, which had been ovariectomized for 2 weeks, were sacrificed at 9.00 h and the preoptic area (POA) and basal hypothalamus (BH) were dissected out and frozen on dry ice. One group of tissues from proestrous control and ovariectomized females were extracted in acetic acid, centrifuged at 13,000 gand the supernatant purified on a C18column. The purified extract was then radioimmunoassayed for proGnRH, using a specific antiserum to rat proGnRH (ARK-2), and for GnRH using the El-14 antiserum. Total cellular RNA was isolated from another group of tissues and prepared as Northern blots. Hybridization with32P-labeled GnRH cRNA was used to detect GnRH mRNA. A third group of proestrous and ovariectomized female rats were perfused, and 50 µm vibratome sections were cut. These were immunostained with proGnRH or GnRH antiserum, followed by in situ hybridization with3SS-labeled GnRH cRNA to detect GnRH mRNA. Based on the histochemical staining, mRNA was colocalized to the cell soma of neurons containing proGnRH and GnRH throughout the POA and BH. Based on the radioimmunoassay, proGnRH levels were 2 times higher in the POA versus the BH, but GnRH levels were 6–7 times higher in the BH. Ovariectomy significantly decreased proGnRH levels in both the POA and BH, while GnRH decreased in the BH. In contrast, quantitative Northern blot analysis demonstrated that ovariectomy had no effect on mRNA levels in the POA and BH. These data indicate that the effects of ovariectomy on proGnRH and GnRH levels are a result of altered translation, posttranslational processing and/or secretion of GnRH.