Methodology for implanting cortisol in Atlantic salmon and effects of chronically elevated cortisol on osmoregulatory physiology
Document Type
Article
Date of Original Version
3-15-1994
Abstract
A method for achieving high physiological concentrations of cortisol in the plasma of Atlantic salmon (Salmo salar) is outlined. Cortisol was emulsified in vegetable shortening:vegetable oil (1 : 1). This mixture is fluid at 24°C and can be injected into the peritoneum where it solidifies into a slow-releasing cortisol implant. Three doses of cortisol implants were used: 25, 50 and 100 μg/g body weight. Salmon in the post-smolt stage were serially sampled in short-term (1 week) and long-term (1 month) experiments. There was significant variability in the vehicle-implanted control fish over time in both experiments. Except for day of the implant, there were no differences between the implanted controls and the non-implanted controls, indicating that the implant itself was probably not stressful. The medium dose (50 μg/g body weight) was found to elevate plasma cortisol within 1 day and to maintain plasma cortisol above vehicle-implanted salmon for as long as 1 month. The low dose was ineffective after 1 week and the high dose resulted in plasma cortisol concentrations above physiological levels. Exogenous cortisol increased the fluid uptake rate of the non-everted posterior intestinal sac after 1 month and increased the gill Na+ K+-ATPase activity after 1 week. These implants might be useful in allowing culturists to move salmon to sea cages at times outside the typical smolt window. © 1994.
Publication Title, e.g., Journal
Aquaculture
Volume
121
Issue
1-3
Citation/Publisher Attribution
Specker, Jennifer L., David M. Portesi, Sean C. Cornell, and Philip A. Veillette. "Methodology for implanting cortisol in Atlantic salmon and effects of chronically elevated cortisol on osmoregulatory physiology." Aquaculture 121, 1-3 (1994). doi: 10.1016/0044-8486(94)90019-1.