Bale T L, Dorsa D M
Department of Pharmacology, University of Washington, Seattle.
Endocrinology. 1995 Jan;136(1):27-32. doi: 10.1210/endo.136.1.7828541.
In situ hybridization techniques were used in the present study to detect hypothalamic expression of the oxytocin receptor (OR) gene. Binding studies have localized OR to various brain regions and have detected a high density of receptors in the ventromedial hypothalamus (VMH), a documented target of estrogen action. This study was designed to compare levels of OR messenger RNA (mRNA) in the VMH of male and female rats and to study the effects of estrogen treatment on mRNA levels in the VMH of female rats. After cloning a rat OR gene from a genomic testes library, a probe was generated for use in in situ hybridization assays to evaluate sex differences in OR mRNA expression in the VMH. In addition, ovariectomized females were treated with estrogen, and VMH OR mRNA expression was compared with that in ovariectomized or intact females. The results of these studies showed that male rats expressed higher levels of OR mRNA in the VMH than females. Estrogen-treated ovariectomized females exhibited significantly greater expression in the VMH than either oil-treated or intact females. These results support binding studies that have shown oxytocin binding in the VMH to be regulated by gonadal steroids and suggest that estrogen may either directly or indirectly regulate transcription of the OR gene.
在本研究中，采用原位杂交技术检测下丘脑催产素受体（OR）基因的表达。结合研究已将OR定位到大脑的各个区域，并在腹内侧下丘脑（VMH）中检测到高密度的受体，VMH是雌激素作用的一个已被证实的靶点。本研究旨在比较雄性和雌性大鼠VMH中OR信使核糖核酸（mRNA）的水平，并研究雌激素处理对雌性大鼠VMH中mRNA水平的影响。从基因组睾丸文库中克隆出大鼠OR基因后，制备了一个探针用于原位杂交分析，以评估VMH中OR mRNA表达的性别差异。此外，对去卵巢的雌性大鼠进行雌激素处理，并将VMH中OR mRNA的表达与去卵巢或未处理的雌性大鼠进行比较。这些研究结果表明，雄性大鼠VMH中OR mRNA的表达水平高于雌性。雌激素处理的去卵巢雌性大鼠VMH中的表达明显高于油处理或未处理的雌性大鼠。这些结果支持了结合研究，即已表明VMH中的催产素结合受性腺类固醇调节，并表明雌激素可能直接或间接调节OR基因的转录。
