期刊名称：Journal of PHYSIOLOGICAL ANTHROPOLOGY and Applied Human Science
印刷版ISSN：1345-3475
出版年度：1996
卷号：15
期号：3
页码：111-114
DOI：10.2114/jpa.15.111
出版社：Japan Society of Physiological Anthropology
摘要：The adaptive response of oxidative enzyme activity in the skeletal muscle to training in normoxic and in normobaric hypoxic training was studied. Forty male Wistar rats were divided into 4 groups: normoxia + sedentary (NS, n=10); hypoxia + sedentary (HS, n=10); normoxia + training (NT, n=10); and hypoxia + training (HT, n=10). Rats in the NT group ran on a treadmill for 30 min a day at 20-30 m·min-1, 4 days a week for 10 weeks in normoxia. Rats in the HT group performed the same training protocol as NT in an ambient FIO2 decreased to 12%. HS rats were exposed to hypoxia in the same degree, duration and frequency as HT without exercise. After the training period, the soleus and the plantaris muscles were removed, and the activities of mitochondrial enzymes, malate dehydrogenase (MDH) and 3-hydroxyacyl-CoA dehydrogenase (HAD) were measured by a spectrophotometer. The normoxic training did not increase MDH or HAD activities, in either the soleus or the plantaris. This absence of change in mitochondrial enzyme activities is considered to be the results of inadequate stimulus of training, including a relatively low amount of exercise. On the other hand, the hypoxie training enhanced the MDH activity in the soleus by 17.5% compared with NS (P<0.01) and by 20.5% compared with HS (P<0.01). Also in the plantaris, the MDH activity in HT was higher than that in HS (15.7%, P<0.05). These findings suggest that even moderate training by which enzyme activity is not increased under normoxic conditions can enhance the oxidative capacity in the skeletal muscle when the training is performed in a hypoxic environment.
