Effects of local muscle activity on glut 4 concentration in skeletal muscle.
- VernacularTitle:局所的な筋活動量の変動による骨格筋糖輸送体濃度の変化
- Author:
KENTARO KAWANAKA
;
MITSURU HIGUCHI
;
SHIGERU KATSUTA
- Publication Type:Journal Article
- Keywords:
tenotomy;
local musle activity;
gastrocnemius muscle;
plantaris muscle;
GLUT4
- From:Japanese Journal of Physical Fitness and Sports Medicine
1993;42(4):389-395
- CountryJapan
- Language:Japanese
-
Abstract:
In the present study, we examined whether GLUT4 concentration in rat skeletal muscle is dependent on local muscle activity level or not. In ten male Sprague-Dawley rats, one side of gastrocnemius muscle was tenotomized, and the other side contralateral muscle was treated sham operation as a control. Gastrocnemius and plantaris muscles were excised from both legs at the five weeks after surgery. After the muscles were weighed, GLUT 4 concentration and citrate synthase (CS) activity were measured. The results are summarized as follows:
In gastrocnemius muscle, tenotomy induced decreases of 25% in muscle weight, 16% in CS activity, and 25% in GLUT 4 concentration as compared with the control muscle. These data suggest that although extramuscular environment is similar, different GLUT 4 concen-tration in both muscles is induced by different muscle activity level. Therefore, it is con-cluded that muscle activity level regulates GLUT 4 concentration in skeletal muscle. In over-loaded synergistic plantaris muscle, muscle weight and GLUT 4 content per whole muscle were increased by 18% and 17%, respectively, but GLUT 4 concentration and CS activity were not changed as compared with the control muscle. These data could be interpreted that GLUT 4 concentration and mitochondrial oxidative enzyme activity in skeletal muscle are coregulated.
