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Effects of long-term cortisol treatment on growth and osmoregulation of Atlantic salmon and brook trout

March 29, 2021

Cortisol is the final product of the hypothalamic-pituitary-interrenal (HPI) axis and acts as a gluco- and mineralo-corticoid in fish. Long-term elevations of cortisol have been linked to reduced growth in fishes, but the mechanism(s) and relative sensitivities of species are still unclear. We carried out experiments to examine the relative effects of cortisol on growth and gill NKA activity in two salmonids: Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis). Treatment with intraperitoneal cortisol implants for 30 days resulted in reduced growth in both species, but with greater sensitivity to cortisol in brook trout. Gill NKA activity was strongly upregulated by cortisol in Atlantic salmon, and weakly upregulated in brook trout but with no statistically significant effect. Cortisol treatment resulted in reduced plasma levels of insulin-like growth factor I and increased plasma growth hormone levels in Atlantic salmon. Our results demonstrate that there are species differences in the sensitivity of growth and osmoregulation to cortisol, even among species in the same family (Salmonidae).

Publication Year 2021
Title Effects of long-term cortisol treatment on growth and osmoregulation of Atlantic salmon and brook trout
DOI 10.1016/j.ygcen.2021.113769
Authors Luis Vargas-Chacoff, Amy M. Regish, A. Weinstock, B Th Bjornsson, Stephen D. McCormick
Publication Type Article
Publication Subtype Journal Article
Series Title General and Comparative Endocrinology
Index ID 70219439
Record Source USGS Publications Warehouse
USGS Organization Eastern Ecological Science Center