The Effect of Vegetable Diet on Some Values of Protein and Fat-Metabolism in Len Rats of Different Age

Veterinarni Medicina 38, 1993, 413-425

Male len rats at the age of 30 - 140 days were administered a diet with an optimum content of nutrients in dependence on their age in which the source of proteins was this: milk casein (essential acid to nonessential acid ratio E/N = 0.79), soya (defatted and without inhibitors of digestive enzymes, E/N = 0.73), wheat gluten (E/N = 0.30), and their mixture (with one-third portions of each protein, E/N = 0.54). The dietary protein values were adjusted to optimum values according to the quality with respect to casein (without amino acid fortification). Protein utilization (net protein ratio NPR) was determined in weekly intervals, triacylglycerol and cholesterol concentrations in the blood serum were determined on the 70th and 140th day of age. A proteosynthesis rate was determined isotopically as L-/U-C-14-tyrosine incorporation in the protein fraction of liver and muscle in 12 hours after intrapentoneal aplication of the isotope in the rats in the period of rapid growth and in the adult rats on a casein - gluten diet. The isotopically determined values of tyrosine in the liver and muscles are significantly lower for the age of 70 days and gluten diet in comparison with the casein values. The proteosynthesis rate at the age of 140 days is identical. A direct relation was also found between protein utilization and the values of the amino acid score of limiting amino acids AS and the potential biological value of the diet BH(p) in growing rats at the age of 30 - 98 days (AS - K/Met + Cys/2/67, S/Met + Cys/2/63, G/Lys/28, mixture/Met+Cys/2/ 67

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