Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, China.
Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, China
J Exp Biol. 2019 May 8;222(Pt 9):jeb200204. doi: 10.1242/jeb.200204.
Effects of ammonia-N (0.05, 2, 10 and 20 mg l) on the neuroendocrine regulation of ammonia transport were investigated in The results showed that corticotrophin-releasing hormone, adrenocorticotropic hormone, dopamine, noradrenaline and 5-hydroxytryptamine concentrations in all ammonia-N groups increased significantly between 3 and 12 h. Cortisol increased significantly between 3 and 24 h. All hormones except crustacean hyperglycemic hormone were reduced to control levels. mRNA abundance of guanylyl cyclase increased significantly during the experiment. Dopamine receptor D and α adrenergic receptor mRNA abundance in treatments decreased significantly at the beginning, and eventually returned to the control level, whereas mRNA abundance of the 5-HT receptor increased significantly only within the first 12 h. Changes in protein kinase (PKA, PKG) mRNA abundance were similar to the patterns of biogenic amines and crustacean hyperglycemic hormone, peaking at 6 and 12 h, respectively, whereas PKC mRNA abundance decreased within 24 h. 14-3-3 protein, FXYD2 and cAMP-response element binding protein mRNA abundance increased significantly and peaked at 6 h. β-catenin and T-cell factor mRNA abundance increased significantly throughout the experiment and peaked at 12 h. The upregulation of Rh protein, K channel, Na/K-ATPase, V-type H-ATPase and vesicle associated membrane protein (VAMP) mRNA, together with downregulation of Na/K/2Cl cotransporter mRNA, indicated an adjustment of general branchial ion-/ammonia-regulatory mechanisms. Meanwhile, hemolymph ammonia concentration was significantly increased in most ammonia-N exposure groups. Histological investigation revealed the hepatopancreatic damage caused by ammonia-N. Results suggest that hormones, biogenic amines and Wnt/β-catenin play a principal role in adapting to ammonia-N exposure and facilitating ammonia transport.
（一）氨氮（0.05、2、10 和 20mg/L）对氨转运的神经内分泌调节作用进行了研究。结果表明，在所有氨氮组中，3 至 12 小时之间促肾上腺皮质释放激素、促肾上腺皮质激素、多巴胺、去甲肾上腺素和 5-羟色胺浓度显著增加。皮质醇在 3 至 24 小时之间显著增加。除甲壳动物高血糖素外，所有激素均降至对照水平。实验过程中鸟苷酸环化酶的 mRNA 丰度显著增加。多巴胺受体 D 和α肾上腺素受体 mRNA 丰度在处理开始时显著降低，最终恢复到对照水平，而 5-HT 受体 mRNA 丰度仅在最初 12 小时内显著增加。蛋白激酶（PKA、PKG）mRNA 丰度的变化与生物胺和甲壳动物高血糖素的模式相似，分别在 6 和 12 小时时达到峰值，而 PKC mRNA 丰度在 24 小时内下降。14-3-3 蛋白、FXYD2 和 cAMP 反应元件结合蛋白 mRNA 丰度显著增加，在 6 小时时达到峰值。β-连环蛋白和 T 细胞因子 mRNA 丰度在整个实验过程中显著增加，并在 12 小时时达到峰值。Rh 蛋白、K 通道、Na/K-ATP 酶、V 型 H-ATP 酶和囊泡相关膜蛋白（VAMP）mRNA 的上调，以及 Na/K/2Cl 共转运体 mRNA 的下调，表明了一般鳃离子/氨调节机制的调整。同时，大多数氨氮暴露组的血淋巴氨浓度显著增加。组织学检查显示氨氮引起的肝胰腺损伤。结果表明，激素、生物胺和 Wnt/β-连环蛋白在适应氨氮暴露和促进氨转运方面发挥着主要作用。
