INFLUENCE OF VARIOUS LEVELS OF LYSINE INTAKE ON WEIGHT GAIN AND BODY COMPOSITION OF RATS

When rats were fed a diet containing a low level of plant protein supplemented with an excessive amount of lysine, growth retardation often occurred as a result of amino acid imbalance. In this study, rats were fed various levels of lysine in 18% of wheat gluten diet. The basal diet contained no supplemental lysine, while the other diets contained the following percentages of supplemental L-lysine: 0.20, 0.4, 0.8, 1.6, and 3.2. Body weight, serum protein, serum albumin, and bone calcium concentrations increased as the amount of lysine in the diet was increased and reached maximum at the 0.4% level of lysine. Lysine supplementation increased urinary lysine excretion most prominently. The concentrations of some other urinary amino acids were also changed but to a lesser degree. Liver glycogen and liver fat were reduced when lysine was included in the diets. © 1969, American Chemical Society. All rights reserved.