Exercise and beta-alanine supplementation on carnosine-acrolein adduct in skeletal muscle

Previous studies have demonstrated that exercise results in reactive aldehyde production and that beta-alanine supplementation increases carnosine content in skeletal muscle. However, little is known about the influence exercise and beta-alanine supplementation have on the formation of carnosine-aldehydes. The goal of the present study was to monitor the formation of carnosine-aldehyde adducts, following high-intensity intermittent exercise, before and after beta-alanine supplementation. Vastus lateralis biopsy samples were taken from 14 cyclists, before and after a 28 day beta-alanine supplementation, following 4 bouts of a 30 s all-out cycling test, and carnosine and CAR-aldehyde adducts [carnosine-acrolein, CAR-ACR (m/z 303), carnosine-4-hydroxy-2-hexenal, CAR-HHE (m/z 341) and carnosine-4-hydroxy-2-nonenal, CAR-HNE (m/z 383)] were quantified by HPLC-MS/MS. beta-alanine supplementation increased muscle carnosine content by similar to 50% (p = 0.0001 vs. Pre-Supplementation). Interestingly, there was a significant increase in post-exercise CAR-ACR content following beta-alanine supplementation (p < 0.001 vs. post-exercise before supplementation), whereas neither exercise alone nor supplementation alone increased CAR-ACR formation. These results suggest that carnosine functions as an acrolein-scavenger in skeletal muscle. Such a role would be relevant to the detoxification of this aldehyde formed during exercise, and appears to be enhanced by beta-alanine supplementation. These novel findings not only have the potential of directly benefiting athletes who engage in intensive training regimens, but will also allow researchers to explore the role of muscle carnosine in detoxifying reactive aldehydes in diseases characterized by abnormal oxidative stress.