Otero-Rodiño Cristina, Librán-Pérez Marta, Velasco Cristina, Álvarez-Otero Rosa, López-Patiño Marcos A, Míguez Jesús M, Soengas José L
Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Spain.
Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Spain.
Comp Biochem Physiol B Biochem Mol Biol. 2016 Sep;199:29-42. doi: 10.1016/j.cbpb.2015.09.008. Epub 2015 Oct 9.
We hypothesize that glucosensor mechanisms other than that mediated by glucokinase (GK) are present in the liver and Brockmann bodies (BB) of rainbow trout, and are affected by stress. We evaluated in these tissues changes in parameters related to putative glucosensor mechanisms based on liver X receptor (LXR), mitochondrial activity, sweet taste receptor, and SGLT-1 6h after intraperitoneal injection of saline solution alone (normoglycaemic treatment) or containing insulin (hypoglycaemic treatment), or d-glucose (hyperglycaemic treatment). Half of tanks were kept at normal stocking density (NSD; 10kgfishmass·m(-3)) whereas the remaining tanks were kept at high stocking density (HSD; 70kgfishmass·m(-3)). The results provide for the first time in fish evidence for the presence of putative glucosensor systems based on mitochondrial activity and sweet taste receptor in liver whereas in BB systems based on LXR, mitochondrial activity, sweet taste receptor, and SGLT-1 could be operative. We also obtained for the first time in fish evidence for the functioning of integrative metabolic sensors in response to changes in nutrient levels since changes in the mRNA abundance of sirtuin 1 (SIRT-1) were observed in response to increased glucose levels. The stress conditions elicited by HSD altered the response of the glucosensor systems based on mitochondrial activity, sweet taste receptor, and SGLT-1 in the liver, and LXR and SGLT-1 in the BB.
我们假设，除了由葡萄糖激酶（GK）介导的机制外，虹鳟鱼的肝脏和布罗克曼体（BB）中还存在葡萄糖传感机制，并且这些机制会受到应激的影响。我们评估了在这些组织中，腹腔注射单独的盐溶液（正常血糖处理）或含胰岛素的盐溶液（低血糖处理）或d-葡萄糖（高血糖处理）6小时后，与基于肝脏X受体（LXR）、线粒体活性、甜味受体和SGLT-1的假定葡萄糖传感机制相关的参数变化。一半的养殖槽保持正常放养密度（NSD；10kg鱼质量·m(-3)），而其余养殖槽保持高放养密度（HSD；70kg鱼质量·m(-3)）。研究结果首次在鱼类中证明了肝脏中存在基于线粒体活性和甜味受体的假定葡萄糖传感系统，而在BB中基于LXR、线粒体活性、甜味受体和SGLT-1的系统可能起作用。我们还首次在鱼类中获得了整合代谢传感器响应营养水平变化而发挥作用的证据，因为观察到随着葡萄糖水平升高，沉默调节蛋白1（SIRT-1）的mRNA丰度发生了变化。高放养密度引起的应激条件改变了肝脏中基于线粒体活性、甜味受体和SGLT-1以及BB中基于LXR和SGLT-1的葡萄糖传感系统的反应。
