Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/21713
標題: 莫三比克吳郭魚適應在不同鹽度環境中腎臟Na+,K+-ATPase之表現
Na+,K+-ATPase expression in kidneys of tilapia(Oreochromis mossambicus) acclimated to environments of different salinities
作者: 鄭惠珍
Cheng, Hui Chen
關鍵字: Na+
滲透壓調節
K+-ATPase
tilapia
renal
salinity
莫三比克吳郭魚
腎臟
鹽度
出版社: 生命科學系
摘要: 中文摘要 莫三比克吳郭魚(Oreochromis mossambicus)是一種廣鹽性魚類,能在鹽度變化劇烈的環境中生存。腎臟則是硬骨魚調節滲透壓的重要器官之一。以往對於魚類滲透壓調節機制的相關研究,多以鰓為主,因此,本研究著眼於腎臟功能的探討:比較(1)長期適應在海水及淡水環境中,廣鹽性莫三比克吳郭魚腎臟之組織結構及Na+,K+-ATPase(NKA)分佈;(2)長期適應在不同鹽度環境中,腎臟NKA由mRNA、蛋白質含量、至活性的變化;及(3)將吳郭魚分別由淡水轉置到半淡鹹水(20‰)或由半淡鹹水轉置到海水(35‰)中,其腎臟NKA活性、蛋白質及mRNA的含量變化。 實驗結果發現:(1)不論是適應在淡水或海水的吳郭魚,其腎臟所具有之各種組織構造均呈現典型淡水魚的型態,而腎小管間NKA分佈的情況也都相同;(2)長期適應在淡水和海水環境中的吳郭魚腎臟NKA的活性與蛋白質含量遠高於在去離子水及半淡鹹水環境中的值,至於NKA mRNA的含量則無顯著差異;(3)由淡水轉置到半淡鹹水的過程中,吳郭魚腎臟NKA活性及蛋白質含量並無顯著的改變;而NKA mRNA的含量,在轉置 6小時之後,各個時間點的值與0小時比較均有顯著差異,且含量均較0小時為低。由半淡鹹水轉置到海水的過程中,吳郭魚腎臟NKA活性有先下降再升高的趨勢,至於腎臟NKA蛋白質含量的變化,則是在整個轉置過程中均無顯著差異;而在NKA mRNA含量的變化則是有先增加後減少的趨勢存在。 環境鹽度變化的實驗顯示:(1)吳郭魚腎臟組織結構及NKA分佈的情況不受環境鹽度影響;(2)至於NKA在腎臟的表現則是受到適應時間長短及鹽度高低的影響:在長期馴化時,NKA活性的高低來自蛋白質含量的多寡;而在短期適應過程中,不論是將吳郭魚轉置在半淡鹹水或是海水中,腎臟中的蛋白質含量並不會有顯著的改變,但在高鹽的海水環境中,會刺激NKA mRNA含量升高,進而使NKA活性升高,以因應高鹽環境中的生理調節機制,此意味著吳郭魚的腎臟為了調節對不同環境中各種離子的吸收,進而調整NKA的表現,以利於腎臟組織對不同離子的調節功能。
Abstract Tilapia(Oreochromis mossambicus)is an euryhaline teleost which is able to survive in environments of different salinities. The kidney, like the gill, plays an important role in osmoregulation of euryhaline fish. In kidneys, Na+,K+-ATPase(NKA) is a primary active ion-transporter, as it is in gills. The purpose of this study is to clarify the structures and localization of NKA in tilapia kidney, and to reveal renal NKA expression in tilapia adapted to water of different salinities (long-term experiment) and changes of renal NKA expression during BW- and SW-adaptation (short-term experiment). The results revealed that﹕(1) similar structures and NKA immunoreaction were found in kidneys of FW- and SW-adapted tilapia﹔(2) in long-term adapted fish, higher renal NKA activities were derived from increasing amounts of NKA protein, data expressed no difference of NKA α1-isoform mRNA abundance﹔(3) there was no significant difference in renal NKA activity as well as protein abundance of tilapia transferred to BW from FW﹐and NKA α1-isoform mRNA amounts decreased significantly 6 hrs after transfer. On the other hand﹐significant increase of NKA activity but not protein abundance occurred at 6 hrs after the fish were transferred from BW to SW﹐and NKA α1-isoform mRNA amount increased significantly 3 hrs, then it decreased 48hrs after transfer. These results indicated that in long-term adapted fish, higher renal NKA activities were derived from increasing amounts of NKA protein; while in short-term acclimation, rapid elevation of renal NKA activities came from the pre-existed protein abundance to meet the physiological demand.
URI: http://hdl.handle.net/11455/21713
Appears in Collections:生命科學系所

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