title: Studies on the early changes in rat hepatic fructose 2,6-bisphosphate and enzymes in response to a high protein diet.
abstract: 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.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002940:Circadian Rhythm; D000242:Cyclic AMP / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects*; D005215:Fasting; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005635:Fructosediphosphates / Q000378:metabolism*; D005943:Gluconeogenesis / Q000187:drug effects; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006598:Hexosediphosphates / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005635:Fructosediphosphates; D005958:Glucosephosphates; D006598:Hexosediphosphates; D019298:Glucose-6-Phosphate; C027652:fructose 2,6-diphosphate; D000242:Cyclic AMP; D006597:Fructose-Bisphosphatase