EFFECTS OF EXERCISE UNDER RESTRICTED FOOD INTAKE ON PROTEIN METABOLISM IN RATS

Abstract

Effects of treadmill running and restricted food intake on the metabolism of protein in several tissues were studied in male Wistar rats, aged 5 weeks and weighing about 100 g. Rats were divided into control group under free food intake (C), sedentary group under restricted food intake (Sr), exercise group under restricted food intake (Er), Food intake was restricted approximately to 66% of fed ad libitum for control group. Exercise program consisted of treadmill running for 60 minutes a day at 30 m/min on 6 days a week for 12 weeks.
A. The effects of sedentary under restricted food intake.
When compared with C
1) Lowering of body weight and increment in mg tissue/g body weight ratios. (M. Gastrocnemius, Liver, Brain, Testis, M. Soleus, M. Plantaris)
2) Significantly low level of protein content in gastrocnemius muscles, liver and kidney.
3) Inhibition in incorporation of ¹⁴C-amino acid mixture into brain and kidney protein in vivo.
B. The effects of exercise under restricted food intake.
i) compared with C
The effects were the same as those of Sr.
ii) compared with Sr
1) Lowering of body weight and increment in mg tissue/g body weight ratios. (Liver, Heart, Kidney, Testis)
2) Significantly low level of protein content in gastrocnemius muscles.
From this study it was suggested that, under the food restriction of long duration, the maintenance of protein content in brain in spite of the decrease of protein content in the other tissues indicated the existence of internal mechanism for life conservation in severe environment. And loaded with exercise under food restriction, protein content in gastra cnemius muscles decreased. Therefore, it was conceivable that skeletal muscles protein was consumed as energy for exercise.