METABOLIC EFFECTS OF DIETARY PROTEIN LEVEL IN COLD-EXPOSED RATS

Abstract

Male albino rats were fed ad libitum isocaloric diets containing 5%, 20%, and 40% protein and 10% corn oil by weight. Measurements were made of nitrogen retention, urine volume, water intake, body composition, and blood levels of glucose, amino nitrogen, and urea at environmental temperatures of 22 ± 2 °C (7 days) followed by 2 ± 1 °C (8 days). Significant metabolic differences were evident among the three dietary groups at 22 °C but these differences were, in general, reduced under conditions of cold exposure. It is of interest that the rats on the 40% protein diet did not exhibit the typical increases in food consumption and urine volume when exposed to cold and, further, that these animals appeared able to maintain body weight and synthesize body fat during cold exposure. It seems that dietary protein level may play an important role during exposure to cold.