Nowak Krzysztof W, Strowski Mathias Z, Switonska Malgorzata M, Kaczmarek Przemyslaw, Singh Vandana, Fabis Marzena, Mackowiak Pawel, Nowak Magdalena, Malendowicz Ludwik K
Department of Animal Physiology and Biochemistry, August Cieszkowski University of Agriculture, 60-637 Poznan, Poland.
Int J Mol Med. 2005 Jun;15(6):969-72.
Orexins are recently identified neuropeptides that appear to play a role in the regulation of energy homeostasis and arousal. They bind to and activate two closely related G protein-coupled receptors (OXR1 and OXR2), previously described as orphans. In this study we examined involvement of orexins in regulation of insulin secretion from rat pancreatic islets utilizing an in situ perfused pancreas and isolated pancreatic islet models. By means of RT-PCR we found that both OXR1 and OXR2 are expressed in rat pancreatic islets. Furthermore, the expression levels of OXR1 were higher than OXR2. In both experimental models applied, orexins A and B (1, 10 and 100 nmol/l) concentration dependently stimulated insulin secretion at two different glucose concentrations (6.66 or 26.4 mmol/l), with orexin A being more potent than orexin B. This study demonstrates that orexins A and B modulate insulin secretion in vitro.
食欲素是最近发现的神经肽，似乎在能量平衡和觉醒调节中发挥作用。它们与两种密切相关的G蛋白偶联受体（OXR1和OXR2）结合并激活，这两种受体以前被称为孤儿受体。在本研究中，我们利用原位灌注胰腺和分离胰岛模型，研究了食欲素在大鼠胰岛胰岛素分泌调节中的作用。通过逆转录聚合酶链反应（RT-PCR），我们发现OXR1和OXR2在大鼠胰岛中均有表达。此外，OXR1的表达水平高于OXR2。在两种应用的实验模型中，食欲素A和B（1、10和100 nmol/L）在两种不同的葡萄糖浓度（6.66或26.4 mmol/L）下均浓度依赖性地刺激胰岛素分泌，食欲素A比食欲素B更有效。本研究表明，食欲素A和B在体外调节胰岛素分泌。
