caa a22 4500 606236872 CHVBK 20210128101250.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s11010-015-2357-7 doi (NATIONALLICENCE)springer-10.1007/s11010-015-2357-7 Dietary supplementation of β-guanidinopropionic acid (βGPA) reduces whole-body and skeletal muscle growth in young CD-1 mice [Elektronische Daten] [Bradley Baumgarner, Alison Nagle, Meagan Quinn, A. Farmer, Stephen Kinsey] Increased AMP-activated protein kinase (AMPK) activity leads to enhanced fatty acid utilization, while also promoting increased ubiquitin-dependent proteolysis (UDP) in mammalian skeletal muscle. β-guanidinopropionic acid (βGPA) is a commercially available dietary supplement that has been shown to promote an AMPK-dependent increase in fatty acid utilization and aerobic capacity in mammals by compromising creatine kinase function. However, it remains unknown if continuous βGPA supplementation can negatively impact skeletal muscle growth in a rapidly growing juvenile. The current study was conducted to examine the effect of βGPA supplementation on whole-body and skeletal muscle growth in juvenile and young adult mice. Three-week old, post weanling CD-1 mice were fed a standard rodent chow that was supplemented with either 2% (w/w) α-cellulose (control) or βGPA. Control and βGPA-fed mice (n=6) were sampled after 2, 4, and 8 weeks. Whole-body and hindlimb muscle masses were significantly (P<0.05) reduced in βGPA-fed mice by 2weeks. The level of AMPK (T172) phosphorylation increased significantly (P<0.05) in the gastrocnemius of βGPA-fed versus control mice at 2 weeks, but was not significantly different at the 4- and 8-week time points. Further analysis revealed a significant (P<0.05) increase in the skeletal muscle-specific ubiquitin ligase MAFbx/Atrogin-1 protein and total protein ubiquitination in the gastrocnemius of βGPA versus control mice at the 8-week time point. Our data indicate that feeding juvenile mice a βGPA-supplemented diet significantly reduced whole-body and skeletal muscle growth that was due, at least in part, to an AMPK-independent increase in UDP. Springer Science+Business Media New York, 2015 β-Guanidinopropionic acid nationallicence Skeletal muscle growth nationallicence Protein turnover nationallicence AMP-activated protein kinase nationallicence Mechanic target of rapamycin complex 1 nationallicence Baumgarner Bradley Division of Natural Sciences and Engineering, University of South Carolina Upstate, 800 University Way, 29316, Spartanburg, SC, USA aut Nagle Alison Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut Quinn Meagan Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut Farmer A. Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut Kinsey Stephen Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 403/1-2(2015-05-01), 277-285 0300-8177 403:1-2<277 2015 403 11010 https://doi.org/10.1007/s11010-015-2357-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 brief-communication jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-015-2357-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baumgarner Bradley Division of Natural Sciences and Engineering, University of South Carolina Upstate, 800 University Way, 29316, Spartanburg, SC, USA aut NATIONALLICENCE 700 1- Nagle Alison Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut NATIONALLICENCE 700 1- Quinn Meagan Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut NATIONALLICENCE 700 1- Farmer A. Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut NATIONALLICENCE 700 1- Kinsey Stephen Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, 28403-5915, Wilmington, NC, USA aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 403/1-2(2015-05-01), 277-285 0300-8177 403:1-2<277 2015 403 11010