Please use this identifier to cite or link to this item:
Title: Nutritional regulation of glucose-6-phosphatase gene expression in liver of the gilthead sea bream (Sparus aurata)
Author: Caseras Surribas, Anna
Metón Teijeiro, Isidoro
Vives, C.
Egea Liria, Miriam
Fernández González, Felipe Javier
Vázquez Baanante, Ma. Isabel
Keywords: Enzimologia
Regulació del metabolisme
Expressió gènica
Nutrició animal
Metabolic regulation
Sparus aurata
Gene expression
Animal nutrition
Issue Date: Dec-2002
Publisher: Cambridge University Press
Abstract: To examine the role of glucose-6-phosphatase (G6Pase) in glucose homeostasis in the diabeteslike experimental model of carnivorous fish, we analysed postprandial variations and the effect of starvation, ration size and diet composition on the regulation of G6Pase expression at the enzyme activity and mRNA level in the liver of gilthead sea bream (Sparus aurata ). G6Pase expression increased in long-term starved or energy-restricted fish. In contrast to data reported for other fish species, short-term regulation of G6Pase expression was found in regularly fed S. aurata. G6Pase mRNA levels were lowest between 4 and 15 h after food intake, whereas minimal enzyme activity was observed 10-15 h postprandially. Alterations of plasma glucose levels affect G6Pase in mammals. However, the carbohydrate content of the diet did not affect hepatic expression of G6Pase in S. aurata, suggesting that a different molecular mechanism is involved in the control of G6Pase expression in fish. Although G6Pase was unaffected, highcarbohydrate low-protein diets increased glucokinase (GK) expression and thus allowed a metabolic adaptation favouring glycolysis over gluconeogenesis. Interestingly, only the nutritional conditions that promoted variations in the blood glucose levels resulted in changes in the hepatic expression of G6Pase. These findings indicate a concerted regulation of G6Pase and GK expression and suggest that the direction and rate of the glucose-glucose-6-phosphate substrate cycle flux is finely regulated in the liver of S. aurata, challenging the role attributed to deficient regulation of G6Pase or GK expression in the low ability of carnivorous fish to metabolize glucose.
Note: Reproducció del document publicat a:
It is part of: British Journal of Nutrition, 2002, vol. 88, num. 6, p. 607-614
Related resource:
ISSN: 0007-1145
Appears in Collections:Articles publicats en revistes (Bioquímica i Biomedicina Molecular)
Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals)

Files in This Item:
File Description SizeFormat 
503136.pdf256.8 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.