Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, PR China.
Mol Cell Endocrinol. 2012 Sep 25;361(1-2):213-8. doi: 10.1016/j.mce.2012.04.012. Epub 2012 May 4.
The aim of this study is to investigate whether galanin (GAL) central receptors are involved in regulation of insulin resistance. To test it, a GAL antagonist, M35 was intracerebroventricularly administrated in trained type 2 diabetic rats. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The epididymal fat pads were processed for determination of glucose uptake and Glucose Transporter 4 (GLUT4) amounts. The Gal mRNA expression levels in hypothalamus were quantitatively assessed too. We found an inhibitory effect of M35 on glucose uptake into adipocytes, Gal mRNA expression levels in hypothalamus, glucose infusion rates in the clamp test and GLUT4 concentration in plasma membranes and total cell membranes of adipocytes. The ratios of GLUT4 contents of the former to the latter in M35 groups were lower. These results suggest a facilitating role for GAL on GLUT4 translocation and insulin sensitivity via its central receptors in rats.
本研究旨在探讨甘丙肽（GAL）中枢受体是否参与调节胰岛素抵抗。为了验证这一点，在训练有素的 2 型糖尿病大鼠中，通过脑室内给予 GAL 拮抗剂 M35 进行实验。通过进行正常血糖高胰岛素钳夹试验来评估葡萄糖输注率。对附睾脂肪垫进行处理以测定葡萄糖摄取量和葡萄糖转运蛋白 4（GLUT4）的含量。还定量评估了下丘脑内的 Gal mRNA 表达水平。我们发现 M35 对脂肪细胞摄取葡萄糖、下丘脑内 Gal mRNA 表达水平、钳夹试验中的葡萄糖输注率以及脂肪细胞质膜和总细胞膜中的 GLUT4 浓度均有抑制作用。M35 组中前者与后者的 GLUT4 含量比值较低。这些结果表明，GAL 通过其中枢受体在大鼠中促进 GLUT4 易位和胰岛素敏感性。
