ABSTRACT The nonapeptide hormone arginine vasotocin (VT) regulates osmotic balance in fishes by modulating ion and water transport. While VT’s osmoregulatory effects arise in part via changes in VT secretion, it remains uncertain which nonapeptide receptors mediate these effects, or whether adjustments in VT degradation also contribute. This study characterized gene transcript profiles for all known teleost nonapeptide receptors and for the VT and isotocin (IT) degradation enzyme leucyl-cystinyl aminopeptidase (lnpep) in the gill, kidney, and intestine – as well as transcriptional profiles for proVT and proIT mRNAs in hypothalamus and pituitary – of blue tilapia (Oreochromis aureus) during hyperosmotic challenge. Results presented here suggest that VT’s actions during salinity acclimation may be mediated by V1a-type receptor V1a2 in gill and intestine but multiple V2-type receptors in kidney, and provide evidence that lnpep expression is modulated concurrent with osmoregulation, possibly to alter local availability of nonapeptides as osmolality returns to homeostatic set points.

中文翻译：

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蓝罗非鱼（Oreochromis aureus）在高盐度驯化过程中编码精氨酸血管收缩素和等收缩素受体以及亮氨酰-胱氨酰氨肽酶（LNPEP）九肽降解酶的基因的表达谱

摘要九肽激素精氨酸血管收缩素 (VT) 通过调节离子和水的运输来调节鱼类的渗透平衡。虽然 VT 的渗透压调节作用部分是通过 VT 分泌的变化产生的，但尚不确定哪些九肽受体介导了这些作用，或者是否对 VT 降解的调整也有贡献。该研究表征了所有已知硬骨鱼九肽受体以及鳃、肾和肠中的 VT 和等产素 (IT) 降解酶亮氨酰-胱氨酰氨肽酶 (lnpep) 的基因转录谱，以及 proVT 和 proIT mRNA 的转录谱。下丘脑和垂体 - 蓝罗非鱼（Oreochromis aureus）在高渗挑战期间。