Affiliation:
1. Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences Borok Russia
2. A.V. Zhirmunsky National Scientifc Center of Marine Biology, Far Eastern Branch Russian Academy of Sciences Vladivostok Russia
3. Institute of Biomedical Chemistry, Russian Academy of Sciences Moscow Russia
Abstract
AbstractTo investigate the stress response and physiological adaptations of goldfish (Carassius auratus) to critical salinity (CS) waters, we analyzed high‐density lipoprotein (HDL) stoichiometry, stress markers (cortisol, glucose), and plasma osmotic properties (Na+, osmolality, water content) using ichthyology, biochemistry, and proteomics approaches. After 21 days of exposure to CS, plasma concentrations of cortisol, glucose, and Na+ increased, indicating stress. Total plasma osmolality (Osmtotal) and osmolality generated by inorganic (Osminorg) and organic osmolytes (Osmorg) also increased, the latter by ~2%. We associated the increase of Osmorg with (1) increased metabolite concentration (glucose), (2) dissociation of HDL particles resulting in increased HDL number per unit plasma volume (~1.5–2‐fold) and (3) increased HDL osmotic activity. HDL remodeling may be the reason for the redistribution of bound and free water in plasma, which may contribute to water retention in plasma and, at the same time, to hemodynamic disturbances under CS conditions. The study's findings suggest that HDL remodeling is an important mechanism for maintaining osmotic homeostasis in fish, which is consistent with current capillary exchange models in vertebrates.
Subject
Aquatic Science,Ecology, Evolution, Behavior and Systematics