TY - JOUR
T1 - Eukaryotic initiation factors and protein synthesis after resistance exercise in rats
AU - Farrell, Peter A.
AU - Hernandez, Jazmir M.
AU - Fedele, Mark J.
AU - Vary, Thomas C.
AU - Kimball, Scot R.
AU - Jefferson, Leonard S.
PY - 2000/3
Y1 - 2000/3
N2 - Translational control of protein synthesis depends on numerous eukaryotic initiation factors (eIFs) and we have previously shown (Am. J. Physiol. Endocrinol. Metab. 276: E721-E727, 1999) that increases in one factor, eIF2B, are associated with increases in rates of protein synthesis after resistance exercise in rats. In the present study we investigated whether the eIF4E family of initiation factors is also involved with an anabolic response to exercise. Male Sprague-Dawley rats either remained sedentary (n = 6) or performed acute resistance exercise (n = 6), and rates of protein synthesis were assessed in vivo 16 h after the last session of resistance exercise. eIF4E complexed to eIF4G (eIF4E · eIF4G), eIF4E binding protein 1 (4E-BP1) complexed to eIF4E, and phosphorylation state of eIF4E and 4E-BP1 (γ-form) were assessed in gastrocnemius. Rates of protein synthesis were higher in exercised rats compared with sedentary rats [205 ± 8 (SE) vs. 164 ± 5.5 nmol phenylalanine incorporated.g muscle-1 · h-1, respectively; P < 0.05]. Arterial plasma insulin concentrations were not different between the two groups. A trend (P = 0.09) for an increase in eIF4E·eIF4G with exercise was noted; however, no statistically significant differences were observed in any of the components of the eIF4E family in response to resistance exercise. These new data, along with our previous report on eIF2B, suggest that the regulation of peptide chain initiation after exercise is more dependent on eIF2B than on the eIF4E system.
AB - Translational control of protein synthesis depends on numerous eukaryotic initiation factors (eIFs) and we have previously shown (Am. J. Physiol. Endocrinol. Metab. 276: E721-E727, 1999) that increases in one factor, eIF2B, are associated with increases in rates of protein synthesis after resistance exercise in rats. In the present study we investigated whether the eIF4E family of initiation factors is also involved with an anabolic response to exercise. Male Sprague-Dawley rats either remained sedentary (n = 6) or performed acute resistance exercise (n = 6), and rates of protein synthesis were assessed in vivo 16 h after the last session of resistance exercise. eIF4E complexed to eIF4G (eIF4E · eIF4G), eIF4E binding protein 1 (4E-BP1) complexed to eIF4E, and phosphorylation state of eIF4E and 4E-BP1 (γ-form) were assessed in gastrocnemius. Rates of protein synthesis were higher in exercised rats compared with sedentary rats [205 ± 8 (SE) vs. 164 ± 5.5 nmol phenylalanine incorporated.g muscle-1 · h-1, respectively; P < 0.05]. Arterial plasma insulin concentrations were not different between the two groups. A trend (P = 0.09) for an increase in eIF4E·eIF4G with exercise was noted; however, no statistically significant differences were observed in any of the components of the eIF4E family in response to resistance exercise. These new data, along with our previous report on eIF2B, suggest that the regulation of peptide chain initiation after exercise is more dependent on eIF2B than on the eIF4E system.
UR - http://www.scopus.com/inward/record.url?scp=0034093436&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034093436&partnerID=8YFLogxK
U2 - 10.1152/jappl.2000.88.3.1036
DO - 10.1152/jappl.2000.88.3.1036
M3 - Article
C2 - 10710401
AN - SCOPUS:0034093436
SN - 8750-7587
VL - 88
SP - 1036
EP - 1042
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 3
ER -