Leptin长形受体mRNA与LHRH在猪前脑内共存

Colocalization of OB-Rb mRNA and LHRH in the Forebrain of Piglets

为了寻找Leptin在下丘脑水平调控生殖内分泌的形态学证据,用原位杂交和免疫组织化学相结合的方法,研究了5头三元杂交仔猪前脑内Leptin长形受体(OB-Rb)mRNA和黄体生成素释放激素(LHRH)免疫反应阳性物质的共存关系.结果表明,OB-Rb mRNA和LHRH免疫反应阳性神经元在下丘脑、海马结构、大脑皮层和杏仁核内共存,即上述结构内一些表达Leptin长形受体mRNA的神经元也含有LHRH免疫反应阳性物质.在下丘脑,双阳性神经元主要位于室旁核、室周核、腹内侧核、外侧区、弓状核;在大脑皮层(额叶和顶叶)内,双阳性神经元主要位于Ⅲ～V层;在海马结构内,双阳性神经元主要位于齿状回的多形层和颗粒层以及海马的锥体细胞层.结果提示,Leptin可能通过其受体直接作用于下丘脑的促性腺激素释放激素(GnRH)神经元调节动物的生殖和内分泌活动.

In order to find the morphological evidence that leptin plays a role in control of reproductive endocrine in the level of the hypothalamus, coexistence of OB-Rb mRNA and LHRH-like immunoreactive （LHRH-IR） in neurons of the pig forebrain was studied by combination of in situ hybridization and immunohistochemistry methods. The results showed that both OB-Rb mRNA and LHRH-IR containing neurons （dual labelled neurons） were seen in the hypothalamus, hippocampal formation, amygdala and cerebral cortex of the pig, and that some neurons expressing OB-Rb mRNA also contained LHRH-IR. It meant coexistence of OB-Rb mRNA and LHRH-IR in these neurons of the pig forebrain. In the hypothalamus, dual labeled neurons were seen in the paraventricular nucleus, periventricular nucleus, ventromedial nucleus, lateral area and arcuate nucleus. In the hippocampal formation, dual labeled neurons were mainly found in the polymorphic layer and the granular layer of the dentate gyrus and in the pyramidal layer of the hippocampus. In the cerebral cortex, dual labeled neurons were mainly observed in the Ⅲ～Ⅴ layers. The results suggested that leptin probably regulate endocrine and reproduction of animal through directly imposing on the GnRH neurons expressing OB-Rb in the hypothalamus.