Abstract
In a previous study, administration of casein hydrolysate to food- deprived rats at a dose of 4 g/kg body wt resulted in an increase in portal plasma glucagon concentration. This was associated with an activation of phosphorylase a and a decrease in hepatic glycogen concentration. The present study was undertaken to determine whether similar results would be obtained with smaller doses. Doses of 1 and 2 g/kg body wt were administered to food- deprived rats. At a dose of 2 g/kg, portal plasma glucagon concentration was significantly elevated. This was associated with a slight increase in phosphorylase a activity (P < 0.05) and a 50% decrease in hepatic glycogen concentration (P < 0.01). At a dose of 1 g casein hydrolysate/kg body wt, changes in portal plasma glucagon concentration, phosphorylase a activity and hepatic glycogen concentration generally were not observed. Hepatic glucose, uridine diphosphoglucose, ATP and glucose-6-phosphate concentrations were unaffected by either dose of casein hydrolysate. The data indicate a dose- response relationship between casein hydrolysate administration and effects on glycogen metabolism in the liver. Protein-induced glycogenolysis is likely to occur when rata ingest a moderate amount of a pure protein meal.
Original language | English (US) |
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Pages (from-to) | 1159-1166 |
Number of pages | 8 |
Journal | Journal of Nutrition |
Volume | 125 |
Issue number | 5 |
State | Published - 1995 |
Keywords
- dietary protein
- glucagon
- glycogen synthase
- glycogenolysis
- rats