Dakic Tamara B, Jevdjovic Tanja V, Peric Mina I, Bjelobaba Ivana M, Markelic Milica B, Milutinovic Bojana S, Lakic Iva V, Jasnic Nebojsa I, Djordjevic Jelena D, Vujovic Predrag Z
Department for Comparative Physiology and Ecophysiology, Faculty of Biology, Institute for Physiology and Biochemistry, University of Belgrade, Studentski trg 16, 11000, Belgrade, Serbia.
Centre for Laser Microscopy, Faculty of Biology, Institute for Physiology and Biochemistry, University of Belgrade, Belgrade, Serbia.
Eur J Neurosci. 2017 Jul;46(1):1730-1737. doi: 10.1111/ejn.13607. Epub 2017 Jun 13.
In the hypothalamus, insulin takes on many roles involved in energy homoeostasis. Therefore, the aim of this study was to examine hypothalamic insulin expression during the initial phase of the metabolic response to fasting. Hypothalamic insulin content was assessed by both radioimmunoassay and Western blot. The relative expression of insulin mRNA was examined by qPCR. Immunofluorescence and immunohistochemistry were used to determine the distribution of insulin immunopositivity in the hypothalamus. After 6-h fasting, both glucose and insulin levels were decreased in serum but not in the cerebrospinal fluid. Our study showed for the first time that, while the concentration of circulating glucose and insulin decreased, both insulin mRNA expression and insulin content in the hypothalamic parenchyma were increased after short-term fasting. Increased insulin immunopositivity was detected specifically in the neurons of the hypothalamic periventricular nucleus and in the ependymal cells of fasting animals. These novel findings point to the complexity of mechanisms regulating insulin expression in the CNS in general and in the hypothalamus in particular.
在下丘脑中，胰岛素在能量稳态中发挥着多种作用。因此，本研究的目的是检测禁食代谢反应初始阶段下丘脑胰岛素的表达情况。通过放射免疫分析和蛋白质免疫印迹法评估下丘脑胰岛素含量。采用实时定量聚合酶链反应检测胰岛素mRNA的相对表达。利用免疫荧光和免疫组织化学法确定下丘脑胰岛素免疫阳性的分布情况。禁食6小时后，血清中葡萄糖和胰岛素水平均下降，但脑脊液中未下降。我们的研究首次表明，虽然循环葡萄糖和胰岛素浓度降低，但短期禁食后下丘脑实质中的胰岛素mRNA表达和胰岛素含量均增加。在禁食动物的下丘脑室周核神经元和室管膜细胞中特异性检测到胰岛素免疫阳性增加。这些新发现表明，一般而言，尤其是下丘脑，调节中枢神经系统中胰岛素表达的机制具有复杂性。
