Studies on the Early Changes in Rat Hepatic Fructose 2,6-Bisphosphate and Enzymes in Response to a High Protein Diet

• Published in: The Journal of nutrition Vol. 116; no. 3; pp. 446 - 454
• Main Authors: Bois-Joyeux, Brigitte, Chanez, Marc, Azzout, Belkacem, Peret, Jean
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.03.1986; American Society for Nutritional Sciences
• Subjects: 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase; Analysis of Variance; Animals; Biological and medical sciences; Circadian Rhythm; cyclic AMP; Cyclic AMP - metabolism; Dietary Carbohydrates - pharmacology; Dietary Proteins - pharmacology; Enzyme Activation - drug effects; Fasting; fructose 2,6-bisphosphate; Fructose-Bisphosphatase - metabolism; Fructosediphosphates - metabolism; Fundamental and applied biological sciences. Psychology; Gluconeogenesis - drug effects; Glucose-6-Phosphate; Glucosephosphates - metabolism; Hexosediphosphates - metabolism; Liver - drug effects; Liver - enzymology; Liver - metabolism; Liver. Bile. Biliary tracts; Male; protein; Rats; Rats, Inbred Strains; starvation; Vertebrates: digestive system; starvation; cyclic AMP; 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase; fructose 2,6-bisphosphate; protein; Fasting; Rat; Enzyme; Liver; Rodentia; Metabolism; Feeding; Proteins; Fructose-2,6-bisphosphatase; Vertebrata; Mammalia; Diet; Cyclic nucleotide; AMP-3',5'
• ISSN: 0022-3166; 1541-6100
• DOI: 10.1093/jn/116.3.446

Pertinent hepatic metabolites and enzymes were examined in rats fed a high carbohydrate (HC) diet and during the first 24 h of either starvation or feeding a high protein (HP) diet. Consumption of the HC diet induced slight but definite 24-h oscillations in hepatic concentrations of cyclic AMP, glycogen, glucose 6-phosphate, fructose 2,6-bisphosphate, fructose 1,6-bisphosphate and phosphoenolpyruvate, as well as the activities of 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase and phosphoenolpyruvate carboxykinase. The transition to starvation or the HP diet induced, within 12 h, concurrent increases in cyclic AMP and phosphoenolpyruvate and decreases in glycogen, glucose 6-phosphate, fructose 6-phosphate, fructose 2,6-bisphosphate and fructose 1,6-bisphosphate. These changes were associated with a decrease in the ratio of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase and an increase in phosphoenolpyruvate carboxykinase. These results suggest that the activity of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle is similar during the first 24 h of starvation or HP consumption.