Comparative effects of whey protein versus L-leucine on skeletal muscle protein synthesis and markers of ribosome biogenesis following resistance exercise.
We compared immediate post-exercise whey protein (WP, 500 mg) versus L-leucine (LEU, 54 mg) feedings on skeletal muscle protein synthesis (MPS) mechanisms and ribosome biogenesis markers 3 h following unilateral plantarflexor resistance exercise in male, Wistar rats (~250 g). Additionally, in vitro experiments were performed on differentiated C2C12 myotubes to compare nutrient (i.e., WP, LEU) and 'exercise-like' treatments (i.e., caffeine, hydrogen peroxide, and AICAR) on ribosome biogenesis markers. LEU and WP significantly increased phosphorylated-rpS6 (Ser235/236) in the exercised (EX) leg 2.4-fold (P < 0.01) and 2.7-fold (P < 0.001) compared to the non-EX leg, respectively, whereas vehicle-fed control (CTL) did not (+65 %, P > 0.05). Compared to the non-EX leg, MPS levels increased 32 % and 52 % in the EX leg of CTL (P < 0.01) and WP rats (P < 0.001), respectively, but not in LEU rats (+15 %, P > 0.05). Several genes associated with ribosome biogenesis robustly increased in the EX versus non-EX legs of all treatments; specifically, c-Myc mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA, Npm1 mRNA, Fb1 mRNA, and Xpo-5 mRNA. However, only LEU significantly increased 45S pre-rRNA levels in the EX leg (63 %, P < 0.001). In vitro findings confirmed that 'exercise-like' treatments similarly altered markers of ribosome biogenesis, but only LEU increased 47S pre-rRNA levels (P < 0.01). Collectively, our data suggests that resistance exercise, as well as 'exercise-like' signals in vitro, acutely increase the expression of genes associated with ribosome biogenesis independent of nutrient provision. Moreover, while EX with or without WP appears superior for enhancing translational efficiency (i.e., increasing MPS per unit of RNA), LEU administration (or co-administration) may further enhance ribosome biogenesis over prolonged periods with resistance exercise.
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
C Brooks
CB
Mobley
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
Carlton D
CD
Fox
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
Richard M
RM
Thompson
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
James C
JC
Healy
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
Vincent
V
Santucci
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
Wesley C
WC
Kephart
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
Anna E
AE
McCloskey
MusclePharm Sports Science Institute, Denver, CO, USA.
Mike
M
Kim
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.|Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, AL, USA.
David D
DD
Pascoe
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.|Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, AL, USA.
Jeffrey S
JS
Martin
MusclePharm Sports Science Institute, Denver, CO, USA.
Jordan R
JR
Moon
Wichita State University, Wichita, KS, USA.
Kaelin C
KC
Young
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA. mdr0024@auburn.edu.|Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, AL, USA. mdr0024@auburn.edu.
Michael D
MD
Roberts
D000818:Animals; D006801:Humans; D007930:Leucine / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D000090243:Nucleophosmin; D014176:Protein Biosynthesis; D051381:Rats; D017208:Rats, Wistar; D055070:Resistance Training; D038601:Ribosomal Protein S6 / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*; D000067816:Whey Proteins / Q000378:metabolism*
C000591280:NOP56 protein, rat; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D038601:Ribosomal Protein S6; D000067816:Whey Proteins; D000090243:Nucleophosmin; D007930:Leucine
Leucine; Muscle protein synthesis; Ribosome biogenesis; Whey protein