2002年
Effects of environmental Ca2+ levels on branchial chloride cell morphology in freshwater-adapted killifish Fundulus heteroclitus
Fisheries Science
- ,
- 巻
- 68
- 号
- 2
- 開始ページ
- 347
- 終了ページ
- 355
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1046/j.1444-2906.2002.00432.x
To examine the involvement of chloride cells in the uptake of Ca2+ in freshwater (FW) killifish, chloride cell morphology was compared in fish acclimated to different defined FW environments with Ca2+ concentrations of either 0.1 mM, 0.5 mM, or 2.5 mM. Numerous chloride cells were detected in whole-mount preparations of the gill filaments, which were stained with an antiserum specific for Na+, K+-ATPase. Chloride cells, located mostly on the afferent-vascular edge of the filaments, were larger at lower Ca2+ concentrations. Electron microscopic observations showed that in the 0.1 mM and 0.5 mM Ca2+ experimental groups, the apical membrane of chloride cells were flat or slightly projecting and equipped with numerous microvilli. In the 2.5 mM Ca2+ group, some chloride cells formed an apical pit, whereas other cells were similar to those observed in the 0.1 mM and 0.5 mM Ca2+ groups. Plasma osmolality decreased with decreasing ambient Ca2+ concentration, suggesting that environmental Ca2+ affects the permeability of the body surfaces. Gill Na+, K+-ATPase activity in the 0.1 mM and 0.5 mM Ca2+ groups were significantly higher than that in the 2.5 mM Ca2+ group, implying the involvement of the Na+-Ca2+ exchanger in Ca2+ uptake in the gills. These findings suggest that chloride cells function as the site for Ca2+ uptake in killifish acclimated to low Ca2+ environments.
- ID情報
-
- DOI : 10.1046/j.1444-2906.2002.00432.x
- ISSN : 0919-9268
- SCOPUS ID : 0036094851