Metabolic Responses of White Rats to Balanced and Imbalanced Protein Fed with Different Carbohydrates in 15% and 5% Fat Diet

Publisher Website
Google Scholar
Abstract
This study was designed to investigate effects of different dietary carbohydrates (fed with 2 levels of fat) on liver lipid changes in male, weanling rats subjected to threonine deficiency; and to observe influences of the amino acid imbalance on responses of certain glycolytic enzyme systems to carbohydrate source. In rats fed low protein, threonine-deficient diets containing 15% of corn oil, moderate amounts of excess lipid accumulated in livers regardless of carbohydrate source (glucose, fructose, or an equal mixture of glucose and fructose). However, when similar diets containing only 5% of corn oil were fed, the effect of threonine deficiency on lipid content of liver depended on the type of dietary carbohydrate: with glucose, no increase in liver lipid; with fructose or sucrose, marked fatty infiltration. The degree of stimulation of the glucose 6-phosphatase and fructose-1,6-diphosphatase enzyme systems by a dietary source of fructose was influenced by both threonine deficiency and level of fat in the diet. Also, in contrast with previous observations with 20% protein diets, responses in fructose-1,6-diphosphatase activity were as great as those in glucose 6-phosphatase activity.