Expression of glucocorticoid receptor in the intestine of a euryhaline teleost, the Mozambique tilapia (Oreochromis mossambicus): effect of seawater exposure and cortisol treatment.
Expression of glucocorticoid receptor in the intestine of a euryhaline teleost, the Mozambique tilapia (Oreochromis mossambicus): effect of seawater exposure and cortisol treatment.
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DOI：
10.1016/j.lfs.2005.09.050
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发表时间：
2006-04
期刊：
影响因子：
6.1
通讯作者：
Hideya Takahashi;T. Sakamoto;S. Hyodo;B. Shepherd;T. Kaneko;E. Grau
中科院分区：
文献类型：
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作者：
Hideya Takahashi;T. Sakamoto;S. Hyodo;B. Shepherd;T. Kaneko;E. Grau
皮质醇可能通过糖皮质激素受体和盐皮质激素受体参与硬骨鱼类肠道水和离子转运。为了更好地了解GR在硬骨鱼肠道中的作用，我们研究了广盐性罗非鱼（Oreochromis mossambicus）的GR在肠道中的定位;（2）环境盐度挑战和皮质醇处理对GR mRNA表达的影响。罗非鱼后肠区GR mRNA丰度高于前肠和中肠。在后肠，GR似乎定位于粘膜层。淡水鱼暴露于海水7天后，血浆皮质醇增加后，后肠GR mRNA水平升高。同样，皮质醇植入淡水罗非鱼7天，肠道GR mRNA升高。这些结果表明，海水驯化是伴随着在肠组织中的GR mRNA丰度的上调，可能是由于皮质醇水平的升高。相反，单次腹腔注射皮质醇到淡水罗非鱼肠道GR mRNA的下降。皮质醇对GR mRNA的下调表明皮质醇对GR表达的自动调节具有双重模式。
Cortisol plays an important role in controlling intestinal water and ion transport in teleosts possibly through glucocorticoid receptor (GR) and/or mineralocorticoid receptor. To better understand the role of GR in the teleost intestine, in a euryhaline tilapia, Oreochromis mossambicus, we examined (1) the intestinal localizations of GR; (2) the effects of environmental salinity challenge and cortisol treatment on GR mRNA expression. The mRNA abundance of GR in the posterior intestinal region of tilapia was found to be higher than that in the anterior and middle intestine. In the posterior intestine, GR appears to be localized in the mucosal layer. GR mRNA levels in the posterior intestine were elevated after exposure of freshwater fish to seawater for 7 days following an increase in plasma cortisol. Similarly, cortisol implantation in freshwater tilapia for 7 days elevated the intestinal GR mRNA. These results indicate that seawater acclimation is accompanied by upregulation of GR mRNA abundance in intestinal tissue, possibly as a consequence of the elevation of cortisol levels. In contrast, a single intraperitoneal injection of cortisol into freshwater tilapia decreased intestinal GR mRNA. This downregulation of the GR mRNA by cortisol suggests a dual mode of autoregulation of GR expression by cortisol.