Modifying Effect of Diet on Daily Variations of Certain Liver Constitutents

Abstract

The sequential effect on certain liver enzymes and on liver glycogen of high-carbohydrate or carbohydrate-free diets. The pattern of glycogen deposition and repletion on the various treatments was indicative of a rapid takeover of gluconeogenic reactions to maintain appreciable glycogen stores during a carbohydrate-free dietary regimen. This ability disappeared following a single high-carbohydrate meal. The activity of glutamic-pyruvic transaminase (GPT) varied significantly with respect to time after feeding. This effect was somewhat modified by the carbohydrate-free, high-fat regimen. Glucose-6-phosphatase (G-6-Pase) activity showed some evidence of substrate induction 24 hours after high-carbohydrate meals, but this also disappeared during carbohydrate-free feeding. Glucose-6-phosphate dehydrogenase (G-6-PDH) exhibited no definite 24-hour pattern, but its activity was depressed considerably during the carbohydrate-free regimen. At 24 hours after a meal of the high-carbohydrate diet, however, G-6-PDH activity was significantly increased over previous values obtained during carbohydrate-free feeding.