Dufourny L, Warembourg M
Inserm U422, Lille, France.
Neuroendocrinology. 1996 Sep;64(3):215-24. doi: 10.1159/000127120.
A double-label immunofluorescence technique was used to determine whether progesterone receptor (PR)-containing neurons in the preoptic area and hypothalamus also contain somatostatin (SOM) in both the male and female guinea pig. Animals were gonadectomized, primed by estradiol to induce PR and injected intracerebroventricularly with colchicine to visualize SOM-immunoreactive (SOM-IR) neurons. The only sites of significant overlap between the two immunoreactivities were the medial preoptic nucleus, the periventricular preoptic and hypothalamic regions, the arcuate nucleus (Ar) and the ventrolateral nucleus (VL). No sex differences were detected at this level. In the preoptic area and the periventricular regions, no SOM-IR neurons were shown to have PR. In the Ar, only very few SOM-IR perikarya were found to be also PR-IR. SOM varicosities appeared in close proximity to neurons with PR-containing nuclei. Within the VL, in the female as well as in the male, many SOM-IR cells were also IR for PR. This colocalization persisted throughout the rostrocaudal extent of the nucleus but our quantification revealed a significant sex difference in the percentage of PR-IR neurons with SOM in the caudal VL. These results provide neuroanatomical evidence that progesterone may exert its effect directly upon more than one third of SOM-synthesizing cells in the medial and caudal regions of VL, a site which plays a key role in the control of sexual behavior.
采用双标记免疫荧光技术，以确定雄性和雌性豚鼠视前区和下丘脑含孕激素受体（PR）的神经元是否也含有生长抑素（SOM）。动物行性腺切除术后，用雌二醇预处理以诱导PR，然后脑室内注射秋水仙碱，使SOM免疫反应性（SOM-IR）神经元可视化。两种免疫反应性显著重叠的唯一部位是视前内侧核、视前和下丘脑室周区域、弓状核（Ar）和腹外侧核（VL）。在此水平未检测到性别差异。在视前区和室周区域，未显示有PR的SOM-IR神经元。在弓状核中，仅发现极少数SOM-IR核周体也为PR-IR。SOM曲张体出现在含PR核的神经元附近。在腹外侧核内，无论雌性还是雄性，许多SOM-IR细胞也为PR免疫反应阳性。这种共定位在整个核的前后范围内持续存在，但我们的定量分析显示，在腹外侧核尾部，含SOM的PR-IR神经元百分比存在显著性别差异。这些结果提供了神经解剖学证据，表明孕激素可能直接作用于腹外侧核内侧和尾部区域三分之一以上合成SOM的细胞，该区域在性行为控制中起关键作用。
