Effects of stress on fish reproduction, gamete quality, and progeny

Endocrine, biotransformation, and oxidative stress responses in salmon hepatocytes exposed to chemically induced hypoxia and perfluorooctane sulfonamide (PFOSA), given singly or in combination

“…The response of fish endocrine systems to stressors may be biphasic (Schreck 2010) and stress has been reported to accelerate reproduction processes in fish, apparently dependent on the fish species, maturational stage and the severity of the stress and stressor (Schreck et al 2001). In this study, a relationship between the endocrine, oxidative and biotransformation responses due to hypoxia exposure was confirmed by PCA plot showing that most gene transcripts are clustered and well explained by the model, with the exception of ERα and gr.…”

“…Changes in ambient oxygen levels are considered a stressor in fish (Cech and Crocker 2002;Fivelstad et al 1999), and stress is generally associated with a decrease in both sex steroid hormones and impaired reproductive responses (Clearwater and Pankhurst 1997;Haddy and Pankhurst 1999;Schreck et al 2001;Wu 2009). The response of fish endocrine systems to stressors may be biphasic (Schreck 2010) and stress has been reported to accelerate reproduction processes in fish, apparently dependent on the fish species, maturational stage and the severity of the stress and stressor (Schreck et al 2001).…”

“…Nevertheless, there is incoherence between mRNA expression and protein levels for Vtg and Zr-protein in the present study, representing the potential shortcomings of using in vitro systems in investigating hormonal systems, since the mechanisms are very complex and often orchestrated by several organs. Furthermore, the endocrine systems are regulated through feedback mechanisms to prevent estrogenic responses during suboptimal physiological conditions (Pankhurst and Munday 2011;Schreck et al 2001). …”

The effect of allostatic load on hypothalamic–pituitary–interrenal (HPI) axis before and after secondary vaccination in Atlantic salmon postsmolts (Salmo salar L.)

“…This seemed to be supported by the fact that secondary and tertiary stress responses as plasma chloride, magnesium, fin rot and mortality, were significantly increased in the "stress and vaccine" group compared to the "vaccine and stress" and the control group. Earlier studies have shown that cortisol is often associated with the detrimental effects of stress including: decreased growth rates, reproductive dysfunction (Morgan et al 1999;Schreck et al 2001;Mommsen et al 1999), increased incidence of disease (Barton 2002;Davis et al 2002Davis et al , 2003Einarsdottir et al 2000a;Einarsdottir et al 2000b;Weyts et al 1999), reduced seawater tolerance (Ventura et al 2011;Iversen et al 2009;Mommsen et al 1999;Redding and Schreck 1983;Sandodden et al 2001) and survival (Iversen et al 2005;Portz et al 2006;Finstad et al 2003;Iversen et al 1998;Hasan and Bart 2007). It has also been suggested that if the fish is not permitted enough time to recover completely after stress, a second, normally nonfatal, stressful occurrence could be fatal (Carmichael 1984), as observed in this experiment.…”

“…Cortisol is often associated with the detrimental effects of stress, including decreased growth, reproductive dysfunction (Morgan et al 1999;Schreck et al 2001;Schreck 2010;Mommsen et al 1999), increased incidence of disease (Barton 2002;Davis et al 2002Davis et al , 2003Einarsdottir et al 2000a;Einarsdottir et al 2000b;Weyts et al 1999), reduced seawater tolerance (Iversen et al 1998;Liebert and Schreck 2006;Sandodden et al 2001) and survival (Iversen et al 2005;Portz et al 2006;Finstad et al 2003;Iversen et al 1998;Hasan and Bart 2007).…”