Comparison of an antioxidant source and antioxidant plus BCAA on athletic performance and post exercise recovery of horses
Date
2022
Authors
Kent, Emily, author
Hess, Tanja, advisor
Coleman, Stephen, committee member
Hamilton, Karyn, committee member
Bruemmer, Jason, committee member
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Abstract
Antioxidant supplementation has been shown to decrease post-exercise oxidative stress but can lead to decreased post-exercise muscle protein synthesis. The objective of this study was to compare the effects of the supplementation with a control feed with low antioxidant content (CON) to a high antioxidant feed (AO), versus a high antioxidant and branched-chain amino acid feed (BCAO) on post-exercise protein synthesis and oxidative stress. Our hypothesis is that supplementing AO with BCAA will reduce oxidative stress without hindering muscle protein synthesis. Eighteen mixed breed conditioned polo horses were assigned to one of the three treatments. All horses consumed the CON diet for 30 days and were then assessed using a lactate threshold test (LT). One hour later and following subsequential LT, horses were assigned to the experimental groups and given their treatments. Follow-up LTs were conducted on days 15 and 30 of supplementation. Blood was collected before, two and four hours after LT, and oxidative stress was assessed by determining glutathione peroxidase, superoxide dismutase and malondialdehyde concentrations by ELISA. Muscle biopsies were taken before and 4 hours after LT and analyzed for the expression of protein synthesis by RT-PCR. Results were analyzed in a mixed model by ANOVA and compared by LSM. A reduction of oxidative stress was found over time (P<0.050) with no treatment effect (P>0.050) when using the measured oxidative stress parameters mentioned above. An upregulation in the production of mRNA transcripts related to muscle protein synthesis after exercise was found for muscle primers CD36, CPT1, PDK4, MyF5, and Myogenin (P<0.050). There was a treatment by exercise effect for MyoD (P=0.0041), where AO was upregulated the most after exercise compared to BCAO and CON. MRF4 had a time by treatment effect (p=0.045) where AO was upregulated from day 0 to day 15 and 30 compared to BCAO and CON. This study demonstrated post-exercise muscle synthesis with no advantage of AO plus BCAA compared to AO.
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Subject
branched-chain amino acids
oxidative stress
antioxidants
polo horses
muscle protein