Cortisol-induced changes in some aspects of the intermediary metabolism of Salvelinus fontinalis

• Published in: General and comparative endocrinology Vol. 82; no. 3; pp. 476 - 486
• Main Authors: Vijayan, M.M., Ballantyne, J.S., Leatherland, J.F.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.06.1991; Elsevier
• Subjects: Animals; Biological and medical sciences; Blood Glucose - metabolism; Drug Implants; Food Deprivation; Freshwater; Fructose-Bisphosphatase - metabolism; Fundamental and applied biological sciences. Psychology; Glucosephosphate Dehydrogenase - metabolism; Glyceraldehyde-3-Phosphate Dehydrogenases - metabolism; Glycerol Kinase - metabolism; Glycogen - metabolism; Hydrocortisone - administration & dosage; Hydrocortisone - pharmacology; Intermediate and energetic metabolism; Liver - drug effects; Liver - metabolism; Metabolisms and neurohumoral controls; Phosphofructokinase-1 - metabolism; Salvelinus fontinalis; Trout - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Liver; Lipids; Cortisol; Glucocorticoid; Freshwater environment; Proteins; Vertebrata; Salvelinus fontinalis; Enzymatic activity; Pisces; Adrenal hormone; Carbohydrate; Intermediary metabolism
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(91)90323-X

Cortisol was administered to brook charr ( Salvelinus fontinalis) in the form of slow-release intraperitoneal implants (a) to investigate the effect of chronic cortisol stimulation (up to 60 days) on various aspects of intermediary metabolism, and (b) to determine whether such cortisol-induced changes were comparable to those seen in chronically fasted charr. Except for fish sampled at 1 and 6 h after implantation, there was no consistent increase in the plasma cortisol levels of the cortisol-implanted animals. Nevertheless, there were significant treatment effects (particularly after 60 days) on certain metabolite levels, and key hepatic enzymes, including a lowering of plasma glucose and hepatic glycogen concentrations, increased activities of FBPase, G6PDH, GK, and G3PDH, and reduced activities of PFK. When taken together these changes are indicative of a direct or indirect gluconeogenic action of cortisol, in which metabolites other than amino acids (possibly glycerol) are utilized as substrates. These metabolic changes differed from those found in food-deprived brook charr which appeared to use proteins, as well as lipids, as energy sources.