•  
  •  
 

TIME COURSE OF MUSCLE PROTEIN SYNTHESIS & RELATED PATHWAY MARKERS IN RESPONSE TO WHEY PROTEIN AND CREATINE IN VITRO

Abstract

BACKGROUND: Whey protein (WP) and creatine (CRE) are supplements known to stimulate muscle protein synthesis (MPS) and enhance exercise performance However, the synergistic effect of these supplements on MPS and mTOR pathway-related markers has yet to be fully elucidated. Therefore, the purpose of this study is to determine if a synergistic effect exists between WP and CRE on MPS and mTOR pathway-related markers associated with skeletal muscle growth. METHODS: C2C12 murine myoblasts were grown to 80% confluency in growth media (GM) containing 10% fetal bovine serum. Upon reaching confluency myoblast were differentiated into myotubes with differentiation media (DM) containing 2% normal horse serum. Mature myotubes were treated with either, control (CTL) containing PBS, whey protein (WP), creatine (CRE), or whey protein + creatine (WP+CRE). Myotubes were collected following 1-, 2-, 4-, 8-, and 24-hours of treatment. Prior to collection, myotubes were pulse labeled with puromycin to assess the MPS response. Puromycin and mTOR pathway-related marker were assessed via western blotting. RESULTS: MPS response measured with puromycin revealed a significant treatment x time interaction, treatment main effect, and time main effect (all p<0.001). For puromycin, l-h WP was significantly higher compared all group (p<0.050), at 4-h WP+CRE was higher than CTL and CRE (p<0.040), and at 24-h WP was higher than CTL and CRE (p<0.040). p70S6K expression revealed a significant time x treatment interaction (p=0.012) and main effect of time (p=0.003) but not treatment (p=0.382). At 1-h both CRE and WP+CRE exhibited higher p70S6K expression compared to CTL (p<0.020). RPS6 expression revealed a significant treatment x time interaction (p=0.009), main effect of treatment (p=0.011), and main effect of time (p<0.001). At 1-h the WP treated group had higher RPS6 expression compared to CTL (p=0.004). 4-EBP1 expression revealed a significant treatment x time (p<0.001), main effect of treatment (p=0.003), and main effect of time (p=0.025). At 2-h, 4-EBP1 expression was higher in CRE compared to CTL (p=0.014) and at 4-h both CRE and WP+CRE was higher than CTL (p=0.030). CONCLUSION: Both WP and CRE stimulate the MPS response at differing time points and WP+CRE exhibited notable synergistic effects at varying time points.

This document is currently not available here.

Share

COinS