The osmorespiratory compromise in the euryhaline killifish: water regulation during hypoxia.

Autor: Wood CM; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA woodcm@zoology.ubc.ca.; Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.; Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada., Ruhr IM; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.; Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester M13 9NT, UK., Schauer KL; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA., Wang Y; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA., Mager EM; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.; Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, TX 76203, USA., McDonald MD; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA., Stanton B; Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA., Grosell M; Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.
Jazyk: angličtina
Zdroj: The Journal of experimental biology [J Exp Biol] 2019 Sep 24; Vol. 222 (Pt 18). Date of Electronic Publication: 2019 Sep 24.
DOI: 10.1242/jeb.204818
Abstrakt: Freshwater- and seawater-acclimated Fundulus heteroclitus were exposed to acute hypoxia (10% air saturation, 3 h), followed by normoxic recovery (3 h). In both salinities, ventilation increased and heart rate fell in the classic manner, while Ṁ O 2  initially declined by ∼50%, with partial restoration by 3 h of hypoxia, and no O 2 debt repayment during recovery. Gill paracellular permeability (measured with [ 14 C] PEG-4000) was 1.4-fold higher in seawater, and declined by 50% during hypoxia with post-exposure overshoot to 188%. A similar pattern with smaller changes occurred in freshwater. Drinking rate (also measured with [ 14 C] PEG-4000) was 8-fold higher in seawater fish, but declined by ∼90% during hypoxia in both groups, with post-exposure overshoots to ∼270%. Gill diffusive water flux (measured with 3 H 2 O) was 1.9-fold higher in freshwater fish, and exhibited a ∼35% decrease during hypoxia, which persisted throughout recovery, but was unchanged during hypoxia in seawater fish. Nevertheless, freshwater killifish gained mass while seawater fish lost mass during hypoxia, and these changes were not corrected during normoxic recovery. We conclude that this hypoxia-tolerant teleost beneficially reduces gill water permeability in a salinity-dependent fashion during hypoxia, despite attempting to simultaneously improve Ṁ O 2 , but nevertheless incurs a net water balance penalty in both freshwater and seawater.
Competing Interests: Competing interestsThe authors declare no competing or financial interests.
(© 2019. Published by The Company of Biologists Ltd.)
Databáze: MEDLINE
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