金钱鱼肾脏多巴胺在环境盐度适应中的研究

肾脏多巴胺系统是机体重要的应激反应系统，对哺乳动物维系体内平衡和体液渗透压的稳定具有重要作用，但这方面的研究在鱼类中知之甚少。申请者前期研究发现，金钱鱼肾脏分泌的多巴胺（DA）参与急性低渗胁迫应答，促进机体适应环境盐度变化。然而，肾脏DA介导的鱼类渗透压调节机制仍有很多科学问题亟待阐明。本研究以广盐性鱼类金钱鱼为研究对象，ELISA法检测长期盐度胁迫下肾脏DA含量变化。利用制备的特异性抗体，结合免疫组织化学、蛋白免疫印迹、RNA干扰以及过表达实验，确定参与盐度应答的受体亚型。利用免疫共沉淀与质谱联用技术，结合课题组已有蛋白质组注释结果，鉴定相应亚型受体的下游互作蛋白，在个体和细胞水平进行功能验证。分析不同环境盐度下钠离子分泌规律，检测相关钠离子通道（NKA & NHE）的表达以及活性变化。最终阐述DA对肾脏中钠离子平衡的调控机制。本研究为探索海洋鱼类的盐度适应性提供新的理论支撑。

As an important stress response system, the renal dopaminergic system seems playing a key role in maintaining homeostasis in mammals, but few relative studies have been performed in the fish. In our previous study, it has been proved that renal dopamine (DA) participates in the response of acute hyposaline stress and promotes the adaptation of organism to fluctuation of environmental salinity. However, the osmoregulation mechanism mediated by renal DA of fish is not still well understood so far. In the present study, we use the spotted scat Scatophagus argus as the research subject to measure the contents of renal DA under long-term salinity stress through ELISA. Using the customized specific antibodies, combined with immunohistochemistry, western blotting, RNA interference and overexpression, the dopamine receptor subtype involved in the adaptive regulation of salinity will be identified. Furthermore, using IP-MS technology to explore the corresponding downstream interaction proteins of the dopamine receptor, and reveal their functional characterization in vivo and in vitro. Moreover, the influence of different environmental salinity on renal sodium ion secretion will be analyzed, and the expression and activity of related sodium channels (NKA & NHE) will be detected. Ultimately, we will explore the mechanism of sodium balance regulating by DA in the kidney. This study will provide new insights into the adaptability to environmental salinity in marine fish.