thumbnail

Rapid activation of gill Na+,K+-ATPase in the euryhaline teleost Fundulus heteroclitus

Journal of Experimental Zoology

By:
,
DOI: 10.1002/1097-010X(20000901)287:4<263::AID-JEZ1>3.0.CO;2-I

Links

Abstract

The rapid activation of gill Na+,K+-ATPase was analyzed in the mummichog (Fundulus heteroclitus) and Atlantic salmon (Salmo salar) transferred from low salinity (0.1 ppt) to high salinity (25-35 ppt). In parr and presmolt, Salmo salar gill Na+,K+-ATPase activity started to increase 3 days after transfer. Exposure of Fundulus heteroclitus to 35 ppt seawater (SW) induced a rise in gill Na+,K+-ATPase activity 3 hr after transfer. After 12 hr, the values dropped to initial levels but showed a second significant increase 3 days after transfer. The absence of detergent in the enzyme assay resulted in lower values of gill Na+,K+-ATPase, and the rapid increase after transfer to SW was not observed. Na+,K+-ATPase activity of gill filaments in vitro for 3 hr increased proportionally to the osmolality of the culture medium (600 mosm/kg > 500 mosm/kg > 300 mosm/kg). Osmolality of 800 mosm/kg resulted in lower gill Na+,K+-ATPase activity relative to 600 mosm/kg. Increasing medium osmolality to 600 mosm/kg with mannitol also increased gill Na+,K+-ATPase. Cycloheximide inhibited the increase in gill Na+,K+-ATPase activity observed in hyperosmotic medium in a dose-dependent manner (10-4 M > 10-5 M > 10-6 M). Actinomycin D or bumetanide in the culture (doses of 10-4 M, 10-5 M, and 10-6 M) did not affect gill Na+,K+-ATPase. Injection of fish with actinomycin D prior to gill organ culture, however, prevented the increase in gill Na+,K+-ATPase activity in hyperosmotic media. The results show a very rapid and transitory increase in gill Na+,K+-ATPase activity in the first hours after the transfer of Fundulus heteroclitus to SW that is dependent on translational and transcriptional processes. (C) 2000 Wiley-Liss, Inc.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Rapid activation of gill Na+,K+-ATPase in the euryhaline teleost Fundulus heteroclitus
Series title:
Journal of Experimental Zoology
DOI:
10.1002/1097-010X(20000901)287:4<263::AID-JEZ1>3.0.CO;2-I
Volume
287
Issue:
4
Year Published:
2000
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
263
Last page:
274
Number of Pages:
12