Effect of beta-alanine and carnosine supplementation on muscle contractility in mice.
OBJECTIVE
Enhanced carnosine levels have been shown to be ergogenic for high-intensity exercise performances, although the role of carnosine in the control of muscle function is poorly understood. Therefore, the aim of this study was to investigate the effect of long-term supplementation with increasing doses of carnosine and beta-alanine on muscle carnosine, anserine, and taurine levels and on in vitro contractility and fatigue in mice.


METHODS
Male Naval Medical Research Institute mice (n = 66) were control fed or supplemented with either carnosine (0.1%, 0.5%, or 1.8%) or beta-alanine (0.6 or 1.2%) in their drinking water for 8-12 wk. Soleus and extensor digitorum longus (EDL) were tested for in vitro contractile properties, and carnosine, anserine, and taurine content were measured in EDL and tibialis anterior by high-performance liquid chromatography.


RESULTS
Only supplementation with 1.8% carnosine and 1.2% beta-alanine resulted in markedly higher carnosine (up to +160%) and anserine levels (up to +46%) compared with control mice. Beta-alanine supplementation (1.2%) resulted in increased fatigue resistance in the beginning of the fatigue protocol in soleus (+2%-4%) and a marked leftward shift of the force-frequency relation in EDL (10%-31% higher relative forces).


CONCLUSIONS
Comparable with humans, beta-alanine availability seems to be the rate-limiting step for synthesis of muscle histidine-containing dipeptides in mice. Moreover, muscle histidine-containing dipeptides loading in mice moderately and muscle dependently affects excitation-contraction coupling and fatigue.
Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium.
Inge
I
Everaert
Sanne
S
Stegen
Bert
B
Vanheel
Youri
Y
Taes
Wim
W
Derave
D000818:Animals; D000861:Anserine / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002336:Carnosine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects*; D018763:Muscle Fatigue / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000378:metabolism; D058573:Performance-Enhancing Substances / Q000494:pharmacology*; D013654:Taurine / Q000378:metabolism; D015091:beta-Alanine / Q000008:administration & dosage / Q000494:pharmacology*
D015415:Biomarkers; D058573:Performance-Enhancing Substances; D015091:beta-Alanine; D013654:Taurine; D002336:Carnosine; D000861:Anserine