ANTARCTIC NOTOTHENIOID FISHES DO NOT DISPLAY METABOLIC COLD ADAPTATION IN HEPATIC

• Main Authors: Leonardo J. Magnoni, J. Magnoni
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2002
• Subjects: Antarctic; Krebs; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.573.8197; http://www.library.umaine.edu/theses/pdf/MagnoniLJ2002.pdf

Antarctic notothenioid fishes present specializations related to their chronically cold environment, such as high lipid content in tissues (predominantly triacylglycerols, TAG). When TAGs are mobilized, they yield fatty acids and glycerol. Fatty acids are the primary fuel of oxidative muscle tissues. Gluconeogenesis from glycerol has not been studied in Antarctic fishes despite the importance of glycerol as a breakdown product of TAGs. To assess the possible importance of glycerol as a substrate for gluconeogenesis and to determine whether this pathway and Krebs cycle are metabolically cold adapted, key hepatic enzyme activities were measured in Antarctic notothenioid fishes (Notothenia coriiceps, Gobionotothen gibberifrons and Chionodraco rastrospinosus) and Subantarctic notothenioid fishes (Dissostichus eleginoides, Patagonotothen ramsayi and Eleginops maclovinus). Citrate synthase, fructose 1,6-biphosphatase, glycerol kinase, and phosphoenolpyruvate