Using physicochemical properties to predict the impact of natural dissolved organic carbon on transepithelial potential in the freshwater rainbow trout (Oncorhynchus mykiss) at neutral and acidic pH.

Autor: Morris C; Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. morris@zoology.ubc.ca., Zulian S; Department of Chemistry and Biochemistry, Wilfrid Laurier University, 75 University Ave. W, Waterloo, ON, N2L 3C5, Canada., Smith DS; Department of Chemistry and Biochemistry, Wilfrid Laurier University, 75 University Ave. W, Waterloo, ON, N2L 3C5, Canada., Brauner CJ; Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada., Wood CM; Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.; Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
Jazyk: angličtina
Zdroj: Fish physiology and biochemistry [Fish Physiol Biochem] 2024 Dec; Vol. 50 (6), pp. 2619-2635. Date of Electronic Publication: 2024 Oct 11.
DOI: 10.1007/s10695-024-01409-3
Abstrakt: Dissolved organic carbon (DOC) is a complex mixture of molecules that varies in composition based on origin as well as spatial and temporal factors. DOC is an important water quality parameter as it regulates many biological processes in freshwater systems, including the physiological function of the gills in fish. These effects are often beneficial, especially at low pH where DOCs mitigate ion loss and protect active ion uptake. DOCs of different compositions and quality have varied ionoregulatory effects. The molecular variability of DOCs can be characterized using optical and chemical indices, but how these indices relate to the physiological effects exerted by DOCs is not well understood. We tested the effects of five naturally sourced DOCs, at both pH 7 and pH 4, on transepithelial potential (TEP) (a diffusion potential between the blood plasma and the external water) in rainbow trout. The five chosen DOCs have been well characterized and span large differences in physicochemical characteristics. Each of the DOCs significantly influenced TEP, although in a unique manner or magnitude which was likely due to their physicochemical characteristics. These TEP responses were also a function of pH. With the goal of determining which physicochemical indices are predictive of changes in TEP, we evaluated correlations between various indices and TEP at pH 7 and pH 4. The indices included: specific absorbance coefficient at 340 nm, molecular weight index, fluorescence index, octanol-water partition coefficient, molecular charge, proton binding index, % humic acid-like, % fulvic acid-like, and % protein-like components by parallel factor analysis on fluorescence data (PARAFAC). Our results demonstrate the novel finding that there are three particularly important indices that are predictors of changes in TEP across pHs in rainbow trout: specific absorbance coefficient at 340 nm, octanol-water partition coefficient; and proton binding index.
Competing Interests: Declarations Conflict of interest The authors declare no competing interests.
(© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)
Databáze: MEDLINE
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