Artículo
Regulation of liver glucokinase activity in rats with fructose-induced insulin resistance and impaired glucose and lipid metabolism
Fecha de publicación:
09/2009
Editorial:
National Research Council Canada-NRC Research Press
Revista:
Canadian Journal Of Physiology And Pharmacology
ISSN:
0008-4212
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
We evaluated the relative role of different regulatory mechanisms, particularly 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFK2/FBPase-2), in liver glucokinase (GK) activity in intact animals with fructose-induced insulin resistance and impaired glucose and lipid metabolism. We measured blood glucose, triglyceride and insulin concentration, glucose tolerance, liver triglyceride content, GK activity, and GK and PFK2 protein and gene expression in fructose-rich diet (FRD) and control rats. After 3 weeks, FRD rats had significantly higher blood glucose, insulin and triglyceride levels, and liver triglyceride content, insulin resistance, and impaired glucose tolerance. FRD rats also had significantly higher GK activity in the cytosolic fraction (18.3 ± 0.35 vs. 11.27 ± 0.34 mU/mg protein). Differences in GK protein concentration (116% and 100%) were not significant, suggesting a potentially impaired GK translocation in FRD rats. Although GK transcription level was similar, PFK2 gene expression and protein concentration were 4- and 5-fold higher in the cytosolic fraction of FRD animals. PFK2 immunological blockage significantly decreased GK activity in control and FRD rats; in the latter, this blockage decreased GK activity to control levels. Results suggest that increased liver GK activity might participate in the adaptative response to fructose overload to maintain glucose/triglyceride homeostasis in intact animals. Under these conditions, PFK2 increase would be the main enhancer of GK activity.
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Articulos(CENEXA)
Articulos de CENTRO DE ENDOCRINOLOGIA EXP.Y APLICADA (I)
Articulos de CENTRO DE ENDOCRINOLOGIA EXP.Y APLICADA (I)
Citación
Francini, Flavio; Castro, María Cecilia; Gagliardino, Juan Jose; Massa, Maria Laura; Regulation of liver glucokinase activity in rats with fructose-induced insulin resistance and impaired glucose and lipid metabolism; National Research Council Canada-NRC Research Press; Canadian Journal Of Physiology And Pharmacology; 87; 9; 9-2009; 702-710
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