Vet Med (Praha). 1993 ; 38(7): 413-25.

[The effect of a vegetarian diet on protein and fat metabolism values in rats of various ages]

KrajcovicovÃ¡-KudlÃ¡ckovÃ¡ M, OzdÃn L.

VÃ½skumnÃ½ Ãºstav vÃ½zivy, Bratislava.

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-14C/-tyrosine incorporation in the protein fractions of liver and muscle in 12 hours after intraperitoneal application 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 BHp 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; BHp-K 70.0; S 65.1; G 54.1; mixture 77.0; NPR/70 days/-K 2.00; S 1.48; G 1.22; mixture 2.07). In adult rats (from the age of 105 days) the utilization of the diet from vegetable sources is equalized with the utilization of the diet from animal sources, hence it does not depend on the aminogram quality. The results demonstrate the insufficiency of vegetable sources of food with respect to proteosynthesis and the content of limiting amino acids (decisive for the synthesis of peptide chains) in the period of the organism development. In adult rats the values of the aminograms of food vegetable sources are sufficiently high with respect to the lower rate of proteosynthesis (not for the growth but for the organism maintenance, tissue regeneration).(ABSTRACT TRUNCATED AT 400 WORDS)