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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #193072
Title: AGE ASSOCIATED DECREASE IN THE CONTRACTION INDUCED EIF4E-4G COMPLEX FORMATION IN SKELETAL MUSCLE

Author
item FUNAI, KATSUHIKO - BOSTON UNIVERSITY
item PARKINGTON, JASCHA - BOSTON UNIVERSITY
item CARAMBULA, SILVIA - TUFTS/HNRCA
item Fielding, Roger

Submitted to: Gerontological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: 11/18/2005
Publication Date: 12/1/2005
Citation: Funai, K., Parkington, J., Carambula, S., Fielding, R.A. 2005. Age associated decrease in the contraction induced eif4e-4g complex formation in skeletal muscle. Gerontological Society of America.45:39.

Interpretive Summary:

Technical Abstract: Sarcopenia, the loss of skeletal muscle mass with age, can be improved with resistance exercise, though the capacity for hypertrophy has been reported to decline in aged animals and humans. The cellular mechanism by which muscle contraction can activate intracellular signaling to induce hypertrophy has been described. In this study, we investigated the effect of age on the association of eukaryotic initiation factor 4E with eukaryotic initiation factor 4G (eIF4E-4G) as well as the activity of its binding protein (4E-BP1) and the activity of glycogen synthase kinase-3 (GSK-3) after a single bout of rat hindlimb muscle contractile activity elicited by high-frequency electrical stimulation (HFES). Tibialis anterior (TA) and plantaris (Pla) muscles from adult (6 months old) and aged (30 months old) Fischer 344 x Brown Norway rats were collected either immediately or 6 hr after HFES. eIF4E-4G association was elevated at 6 hr recovery in TA (1.9+/-0.2-fold, P<0.05) and both immediately and 6hr after exercise in Pla (2.1+/-0.3-fold and 2.1 +/- 0.7-fold, P<0.05) in adult rats but no significant increase was observed in aged rats. 4E-BP1 phosphorylation increase was observed only 6 hr after HFES in TA (5.0+/-2.0-fold, P<0.05) in adult rats. GSK-3 phosphorylation was increased both immediately and 6 hr after contraction in both TA (1.6+/-0.3-fold and 4.1+/-0.8-fold, P<0.05) and Pla (1.7+/-0.2-fold and 2.1+/-0.4-fold, P<0.05) in adult rats and remained unchanged in aged rats. These observations confirm that the anabolic response to muscle contraction is attenuated with aging and may explain the reduced capacity for hypertrophy in aged animals.