Rance N E, Young W S
Department of Pathology, University of Arizona College of Medicine, Tucson 85724.
Endocrinology. 1991 May;128(5):2239-47. doi: 10.1210/endo-128-5-2239.
We have previously described hypertrophy of neurons containing estrogen receptor mRNA in the infundibular nucleus of postmenopausal women. In the present investigation we identified peptide mRNAs in the hypertrophied neurons and determined whether postmenopausal neuronal hypertrophy was accompanied by changes in gene expression. In the first study in situ hybridization was performed on sections from hypothalami of postmenopausal women (n = 3) using synthetic 35S-labeled cDNA probes complementary to mRNAs encoding estrogen receptor, substance-P (SP), neurokinin-B (NKB), POMC, cholecystokinin, dynorphin, CRF, enkephalin, galanin, neuropeptide-Y, GH-releasing hormone, and tyrosine hydroxylase. Neuronal cross-sectional areas and cell densities were measured with the aid of a computer microscope system. Neurons labeled with the NKB and SP probes were comparable in size, morphology, and distribution to the hypertrophied neurons containing estrogen receptor mRNA. In contrast, neurons labeled with other cDNA probes were sparsely distributed (CRF and dynorphin), smaller in size (neuropeptide-Y, galanin, GH-releasing hormone, enkephalin, cholecystokinin, and POMC), or located anterior to the hypertrophied population (tyrosine hydroxylase). In the second study sections from hypothalami of premenopausal (n = 3) and postmenopausal (n = 3) women were incubated with cDNA probes complementary to SP or NKB mRNAs. The mean cross-sectional areas of postmenopausal infundibular neurons containing NKB and SP mRNAs increased to 194% and 176% of premenopausal values, respectively. The autoradiographic grain densities of infundibular neurons labeled with either probe were also significantly increased in the postmenopausal group. Finally, the numbers of labeled neurons/tissue increased 6-fold (SP) and 15-fold (NKB) in the postmenopausal infundibular nucleus. These data demonstrate that human menopause is associated with marked increases in hypothalamic NKB and SP gene expression. We propose that neurons containing estrogen receptor, SP, and NKB mRNAs participate in the hypothalamic circuitry regulating estrogen negative feedback in the human.
我们之前曾描述过绝经后女性漏斗核中含有雌激素受体mRNA的神经元肥大现象。在本研究中，我们鉴定了肥大神经元中的肽类mRNA，并确定绝经后神经元肥大是否伴有基因表达的变化。在第一项研究中，使用与编码雌激素受体、P物质（SP）、神经激肽B（NKB）、促肾上腺皮质激素原（POMC）、胆囊收缩素、强啡肽、促肾上腺皮质激素释放因子（CRF）、脑啡肽、甘丙肽、神经肽Y、生长激素释放激素和酪氨酸羟化酶的mRNA互补的合成35S标记cDNA探针，对绝经后女性（n = 3）下丘脑切片进行原位杂交。借助计算机显微镜系统测量神经元的横截面积和细胞密度。用NKB和SP探针标记的神经元在大小、形态和分布上与含有雌激素受体mRNA的肥大神经元相当。相比之下，用其他cDNA探针标记的神经元分布稀疏（CRF和强啡肽）、体积较小（神经肽Y、甘丙肽、生长激素释放激素、脑啡肽、胆囊收缩素和POMC）或位于肥大神经元群体前方（酪氨酸羟化酶）。在第二项研究中，将绝经前（n = 3）和绝经后（n = 3）女性下丘脑切片与与SP或NKB mRNA互补的cDNA探针孵育。绝经后漏斗核中含有NKB和SP mRNA的神经元平均横截面积分别增加到绝经前值的194%和176%。绝经后组中用任一探针标记的漏斗核神经元的放射自显影片颗粒密度也显著增加。最后，绝经后漏斗核中标记神经元/组织的数量增加了6倍（SP）和15倍（NKB）。这些数据表明，人类绝经与下丘脑NKB和SP基因表达的显著增加有关。我们提出，含有雌激素受体、SP和NKB mRNA的神经元参与了人类下丘脑调节雌激素负反馈的神经回路。
