Expression of prolactin-releasing peptide and prolactin in the euryhaline mudskippers (Periophthalmus modestus):: prolactin-releasing peptide as a primary regulator of prolactin
Expression of prolactin-releasing peptide and prolactin in the euryhaline mudskippers (Periophthalmus modestus):: prolactin-releasing peptide as a primary regulator of prolactin
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DOI：
10.1677/jme.1.01768
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发表时间：
2005-06-01
影响因子：
3.5
通讯作者：
Ando, M
中科院分区：
文献类型：
--
作者：
Sakamoto, T;Amano, M;Ando, M
催乳素(PRL)释放肽(PrRP)是硬骨鱼垂体PRL转录和分泌的一种强有力的候选刺激因子。然而，即使在哺乳动物中，控制垂体外催乳素表达的作用也是不清楚的。为了研究PrRP-PRL轴可能不仅存在于脑-垂体部，也存在于外周器官中，研究了PrRP、PRL和生长激素(GH)在两栖真盐藻中的表达模式。PrRP mRNA不仅在脑中大量表达，而且在肝脏、肠道和卵巢中也有丰富的表达，而在皮肤和肾脏中的表达较少。与PrRP基因的分布相对应，PRL基因在这些器官中也可检测到。在对不同环境的适应过程中，PrRP在脑-垂体、肝脏和肠道中的mRNA水平的变化与PRL的变化是以器官特异性的方式平行的。在淡水和陆地条件下，脑组织PrRP和脑垂体催乳素基因的表达增加(P<；0.05)，淡水鱼肠道PrRP和PRL的表达高于海水鱼(P<；0.05)，而离水鱼无明显变化，肝脏则无明显变化。GH的表达与PrRP无相关性。在肠道中，PrRP和PRL似乎共同定位于粘膜层，特别是在粘液细胞中。因此，PrRP也可能是垂体外PRL表达的局部调节器，在环境适应过程中，不同器官中的PrRP-PRL轴可能发挥着器官特异性的作用。
Prolactin (PRL)-releasing peptide (PrRP) is a strong candidate stimulator of pituitary PRL transcription and secretion in teleosts. However, the role in control of extrapituitary PRL expression is unclear even in mammals. To study the possible presence of PrRP-PRL axes not only in the brain-pituitary but also in peripheral organs, the expression patterns of PrRP, PRL and growth hormone (GH) were characterized in amphibious euryhaline mudskippers (Periophthalmus modestus). PrRP mRNA is abundantly expressed not only in the brain but also in the liver, gut and ovary, while less abundant expression was also detected in the skin and kidney. Corresponding to the distribution of PrRP mRNA, PRL mRNA was also detectable in these organs. During adaptation to different environments, the changes in mRNA levels of PrRP paralleled those in PRL in the brain-pituitary, liver and gut in an organ-specific manner. Brain PrRP mRNA and the pituitary PRL mRNA increased under freshwater and terrestrial conditions (P < 0.05); expression of PrRP and PRL in the gut of freshwater fish was higher (P < 0.05) than those in sea-water fish although there were no changes in fish kept out of water; no significant change was seen in the liver. Expressions of GH were not correlated with PrRP. In the gut, PrRP and PRL appear to be co-localized in the mucosal layer, especially in the mucous cells. Thus, PrRP may also be a local modulator of extrapituitary PRL expression and the PrRP-PRL axes in various organs may play an organ-specific role during environmental adaptation.