Regulation of the cortisol stress response during and after exposure to chronic and severe hypoxia in crucian carp (Carassius carassius) and goldfish (Carassius auratus)

Date

2019-09-11

Authors

Alcorn, Michael

Journal Title

Journal ISSN

Volume Title

Publisher

University of Guelph

Abstract

To reduce energy utilization and survive extended periods without oxygen, hypoxia-tolerant animals must regulate the production of the catabolic stress hormone, cortisol. To quantify this response, crucian carp and goldfish were exposed to chronic hypoxic conditions and either sampled immediately or recovered in normoxia. While crucian carp reduced plasma cortisol levels in response to anoxia, severe hypoxia and early reoxygenation increased the circulating levels of cortisol in goldfish. In both species, the first 24 h of recovery were also characterized by a general reduction in head kidney steroidogenic enzyme expression. In contrast, recovery was associated with marked increases in the expression of genes involved in cortisol catabolism and in the mRNA levels of liver leptin, a known inhibitory cytokine of the stress response. These results suggest crucian carp and goldfish utilize several mechanisms to regulate the production of cortisol during and after severe hypoxia exposure.

Description

Keywords

Cortisol, Stress, Fish, Hypoxia, Leptin

Citation