The Effects of Cortisol on Hepatocyte Metabolism in Rainbow Trout: A Study Using the Steroid Analogue RU486

Glucocorticoid receptor activation following elevated oocyte cortisol content is associated with zygote activation, early embryo cell division, and IGF system gene responses in rainbow trout

“…The oocyte concentrations of the steroid RU486 could not be measured, but it was assumed that the partitioning of RU486 between the ovarian fluid and the ooplasm was similar to that for cortisol. The concentration of RU486 in the ovarian fluid was in a range that has been shown to have antagonistic effects on GR function in several species of fish (Vijayan et al 1994, Aluru et al 2004, Scott et al 2005, Veillette et al 2007, Vizzini et al 2007, Alderman et al 2012.…”

“…This study provided evidence that suggests a key role for GR in the modulation of growth, possibly via changes in the expression of several IGF system-related genes, including both the genes that encode for the peptide hormones, IGF1 and 2, and their protein receptors. An important component of the study was the use of the progesterone receptor (PR) and GR antagonist, RU486 (mifepristone), which has been used previously for the evaluation of GR function in fish and mammals (Vijayan et al 1994, Pariante et al 2001, Aluru et al 2004, Scott et al 2005, Veillette et al 2007, Vizzini et al 2007, Peeters et al 2008, Du et al 2009, Alderman et al 2012. Table 3 The effects of in ovo cortisol and RU486 treatment on the correlation between the expressions of igf system genes and gr genes in 7-days post-fertilization (dpf) embryos The antagonistic properties of RU486 on PRs and GRs are complex and still not fully understood; the PR antagonistic action of RU486 has received most attention (reviewed by Leonhardt & Edwards (2002)).…”

Endocrine, Physiological and Histopathological Responses of Fish and their Larvae to Stress with Emphasis on Exposure to Crude Oil and Various Petroleum Hydrocarbons

“…In gluconeogenesis, free amino acids act as precursors for glucose synthesis and the regulation of this process in the liver is suggested to be mediated by cortisol (Lidman et al 1979;Murat et al 1981). The gluconeogenic action of cortisol was supported in studies by Vijayan et al (1994) when a corticosteroid antagonist inhibited the increased alanine gluconeogenesis in cortisol-treated fish.…”

“…The chromaffin cells are innervated by preganglionic cholinergic fibres of the sympathetic nervous system which stimulate catecholamine release into circulation (Nilsson et al 1976). A rapid and dramatic increase in circulating catecholamines can occur in response to a variety of physical stressors such as forced swimming and handling (Mazeaud et al 1977;Hughes et al 1988;Vijayan and Moon, 1994) and forceful exercise (Butler et al 1986;Primmett et al 1986;Tang and Boutilier, 1988;Wood et al 1990). These responses are likely to be a reflection of the oxygen status of the fish.…”

Stress reaction in freshwater fish in response to extreme impacts and during the reproduction period

“…The amino acids released from proteins metabolize fast resulting in the negative nitrogen balance. These catabolic processes are determined by the induction of enzymes, especially of the enzymes responsible for catabolism of amino acids and for gluconeogenesis [39,55,56]. As a result, the synthesis of proteins is suppressed which leads to the growth rate retardation.…”