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Energetic cost of intestinal ion transport pathways in marine teleosts
Author(s) -
Grosell Martin
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.728.1
Subject(s) - osmoregulation , biology , metabolic rate , metabolic pathway , gill , range (aeronautics) , fish <actinopterygii> , marine fish , zoology , ecology , biochemistry , metabolism , fishery , salinity , endocrinology , materials science , composite material
A number of studies have attempted to determine the metabolic cost of osmoregulation in teleost fish by measuring standard or resting metabolic rates with the anticipation that metabolic demands would be lowest at isosmotic salinities. However, there is no consensus among these studies and estimates of osmoregulatory costs based on whole animal metabolic rates range from a 2–30% of resting metabolic rates. Both interspecies differences and difficulties in determining true standard metabolic rates not influenced by spontaneous activity/anxiety/stress contributes to the lack of consensus in field. Isolated osmoregulatory tissues have rarely been employed even though they avoid problems of organismal responses. The few studies using isolated tissues have focused on the gills and estimate cost in the range of 2–4%, a range that matches theoretical considerations. Such low metabolic demands are challenging to capture by measurements of intact animals. To date, no studies have attempted to quantify the metabolic demand of osmoregulatory processes by the marine teleost intestine despite its central role in osmoregulation. Multiple parallel Cl − uptake pathways with different energetic efficiency are present in the marine teleost intestinal epithelium and suggests osmoregulatory metabolic demands comparable to that of the gill tissue. The least expensive Cl − uptake pathway is via NKCC2 consuming 0.17 ATP/Cl − while anion exchange via SLC26a6 is consuming ≥ 1 ATP/Clyet, marine teleost fish employ the SLC26a6 pathway extensively. The theoretical intestinal contribution to marine teleost osmoregulation and the seemingly energetically expensive strategy of employing anion exchange will be presented. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .