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Effects of Resting Muscle Carnosine Content on the Intramuscular Antioxidant Response to a Bout of Resistance Exercise
Author(s) -
Varanoske Alyssa N,
Hoffman Jay R,
Church David D,
Jajtner Adam R,
Townsend Jeremy R,
Beyer Kyle S,
Oliveira Leonardo P,
Fukuda David H,
Stout Jeffrey R
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.707.2
Subject(s) - superoxide dismutase , oxidative stress , carnosine , antioxidant , medicine , muscle biopsy , chemistry , catalase , endocrinology , biochemistry , biopsy
Acute bouts of resistance exercise can result in elevations in oxidative stress. Carnosine (CARN) is a histidine dipeptide that has been suggested to have antioxidant properties, and as a result may enhance the recovery processes following exercise. However, there appears to be only limited data that has examined the effect of resting muscle CARN content on its role as an antioxidant or reducing oxidative stress following an acute bout of resistance exercise. The purpose of this study was to compare the effects of high (HI) and low (LO) resting muscle CARN on antioxidant status. A secondary purpose was to compare the intramuscular oxidative stress response following an acute bout of resistance exercise between individuals with HI and LO CARN values. METHODS Fifteen recreationally‐active men volunteered for this study. Muscle biopsies were sampled from the vastus lateralis of the left leg at baseline (BL). A subset of these participants (n=12) then completed an acute muscle‐damaging protocol consisting of the squat (6 sets × 10 repetitions), leg press (4 sets × 10 repetitions) and leg extension (4 sets × 10 repetitions) exercises at 70% of their 1‐repetition maximum. Additional muscle biopsies were sampled at one (1H), five (5H), and 24 (24H) hours post‐exercise. Intramuscular CARN content from biopsy samples was determined via high‐performance liquid chromatography, whereas glutathione (GSH), catalase (CAT), peroxiredoxin 2 (PRX2), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and thioredoxin 1 (TRX1) were quantified via enzyme‐linked immunosorbent assays. Participants were categorized into HI (n=7; 21.7±2.9 y; CARN: 14.8±4.2 mmol·kg −1 ww) and LO (n=8; 21.8±2.5 y; CARN: 6.4±2.3 mmol·kg −1 ww) groups by their BL CARN levels. Magnitude‐based inferences were used to analyze group differences and change scores in antioxidant concentrations at BL and after exercise. RESULTS Subjects with HI CARN had “Likely” greater GSH at BL compared to those with LO CARN (11.50±2.71 μM vs. 8.75±3.75 μM, respectively). In individuals who completed the resistance exercise protocol, GSH values at 1H were “Likely” greater in individuals with HI CARN compared to those with LO CARN. Decreases in CAT, PRX2, SOD1, and TRX1 from BL to 24H were all “Likely” greater in individuals with HI CARN compared to those with LO CARN. Furthermore, changes in SOD2 from BL to 1H, BL to 5H, and BL to 24H were “Very Likely”, “Likely”, and “Very Likely” lower in individuals with HI CARN compared to those with LO CARN, respectively. DISCUSSION In conclusion, individuals with HI CARN at BL appear to exhibit a differential antioxidant recovery response to resistance exercise compared to individuals with LO CARN.