흰쥐에 있어서 굶주린 때의 산소 소비량, 몸 무게, 신체밀도, 조직 단백질 함유량의 변화

Abstract

Measurements of oxygen consumption, total body density, tissue density and tissue protein content were made on two groups of rats: the first group was the normal control group and the second group was starved for 6 days with free access to water. After the measurement of oxygen consumption animals were sacrificed and the determination of lean body mass (LBM) was made by means of underwater weighing. Comparisons were made between the control and fasted group. The following results were obtained. 1. Total energy expenditure of rat decreased as the fasting progressed. This decrease was parallal to decrease in lean body mass. 2. Although the decrease in oxygen comsumption was parallel to the decrease in gross body weight, the change of lean body mass correlated more closely with the oxygen consumption. 3. Subsequently, oxygen consumption expressed on the basis of both gross body weight or-lean body mass did not decrease as compared to the control value. Oxygen consumption expressed on the basis of body surface area decreased as the fasting progressed. Body surface area was not a good reference expressing oxygen consumption in fasting of the rats. 4. Total body density increased in the fasted group. This reflected the decrease in fat when fasting continued. 5. Tissue density of liver and muscle (gastrocnemius) decreased and that of skin increased in the fasted rats. 6. Protein contents of tissues showed variable changes in acute fasting: liver showed no change, muscle showed a decrease and skin showed an increase. 7. Tissue protein content, which is one component of lean body mass, influenced the changes of tissue density. 8. Total body density was the sum of tissue density.