Changes in insulin-stimulated glucose transport and GLUT-4 protein in rat skeletal muscle after training.
J Appl Physiol (1985)
; 83(6): 2043-7, 1997 Dec.
Article
em En
| MEDLINE
| ID: mdl-9390979
ABSTRACT
After running training, which increased GLUT-4 protein content in rat skeletal muscle by <40% compared with control rats, the training effect on insulin-stimulated maximal glucose transport (insulin responsiveness) in skeletal muscle was short lived (24 h). A recent study reported that GLUT-4 protein content in rat epitrochlearis muscle increased dramatically ( approximately 2-fold) after swimming training (J.-M. Ren, C. F. Semenkovich, E. A. Gulve, J. Gao, and J. O. Holloszy. J. Biol. Chem. 269, 14396-14401, 1994). Because GLUT-4 protein content is known to be closely related to skeletal muscle insulin responsiveness, we thought it possible that the training effect on insulin responsiveness may remain for >24 h after swimming training if GLUT-4 protein content decreases gradually from the relatively high level and still remains higher than control level for >24 h after swimming training. Therefore, we examined this possibility. Male Sprague-Dawley rats swam 2 h a day for 5 days with a weight equal to 2% of body mass. Approximately 18, 42, and 90 h after cessation of training, GLUT-4 protein concentration and 2-[1,2-3H]deoxy-D-glucose transport in the presence of a maximally stimulating concentration of insulin (2 mU/ml) were examined by using incubated epitrochlearis muscle preparation. Swimming training increased GLUT-4 protein concentration and insulin responsiveness by 87 and 85%, respectively, relative to age-matched controls when examined 18 h after training. Forty-two hours after training, GLUT-4 protein concentration and insulin responsiveness were still higher by 52 and 51%, respectively, in muscle from trained rats compared with control. GLUT-4 protein concentration and insulin responsiveness in trained muscle returned to sedentary control level within 90 h after training. We conclude that 1) the change in insulin responsiveness during detraining is directly related to muscle GLUT-4 protein content, and 2) consequently, the greater the increase in GLUT-4 protein content that is induced by training, the longer an effect on insulin responsiveness persists after the training.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte de Monossacarídeos
/
Músculo Esquelético
/
Glucose
/
Hipoglicemiantes
/
Insulina
/
Proteínas Musculares
Limite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Assunto da revista:
FISIOLOGIA
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Japão