Aseptic Inflammation, Skeletal Muscle Damage, Skeletal Muscle Function
Conditions
Keywords
muscle injury, exercise, redox status, immune cells
Brief summary
In this investigation the investigators utilized N-acetylcysteine (NAC) supplementation to enhance reduced glutathione (GSH) stores during an 8-day recovery period from a strenuous eccentric exercise protocol in order to test the hypotheses: i) redox status perturbations in skeletal muscle are pivotal for the immune responses and ii) antioxidant supplementation may alter immune cell responses following exercise-induced muscle microtrauma.
Detailed description
The major thiol-disulfide couple of GSH and oxidized glutathione (GSSG) is a crucial regulator of the main transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle following aseptic injury. Antioxidant supplementation may hamper exercise-induced inflammatory responses. The objective was to examine how thiol-based antioxidant supplementation affects immune mobilization following exercise-induced skeletal muscle microtrauma. In a two-trial, double-blind, crossover, repeated measures design, 10 young men received either placebo or NAC (20 mg/kg/day) immediately after a muscle-damaging exercise protocol (300 eccentric contractions) and for eight consecutive days. Blood sampling and performance assessment were performed pre-exercise, 2h post-exercise and daily for 8 consecutive days.
Interventions
DIETARY_SUPPLEMENTn-acetylcysteine
20 mg//kg/day, orally, daily for eight days following exercise
DIETARY_SUPPLEMENTPlacebo
500 mL orally, daily for eight days following exercise
Sponsors
National and Kapodistrian University of Athens
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Recreationally trained (VO2max \> 45 ml/kg/min) * Engaged in regular exercise for ≥3 times/week for \> 12 months * non-smokers * Abstain from exercise during the course of the two trials * No consumption of performance-enhancing substances, antioxidants, caffeine, alcohol and/or medications during the study.
Exclusion criteria
* NAC intolerance * Recent musculoskeletal injuries of the lower limbs * Febrile illness * History of muscle lesion.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in 11B+ macrophage count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of 11B+ macrophage count in blood |
| Changes in T cytotoxic cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of T cytotoxic cell count in blood |
| Changes in natural killer-T (NK-T) cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of NK-T cell count in blood |
| Changes in 62L macrophage count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of 62L macrophage count in blood |
| Changes in B lympho cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of B lympho cell count in blood |
| Changes in HLA+/Macr+ macrophage count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of HLA+/Macr+ count in blood |
| Changes in natural killer (NK) cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of natural killer cell count in blood |
| Changes in protein carbonyls in red blood cells | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Concentration of protein carbonyls |
| Changes in macrophage count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of macrophage count in blood |
| Changes in thiobarbituric acid reactive substances in red blood cells | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Thiobarbituric acid reactive substances concentration in red blood cells |
| Changes in total antioxidant capacity in serum | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | — |
| Changes in reduced glutathione in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Concentration of reduced glutathione in red blood cells |
| Changes in oxidized glutathione in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Concentration of oxidized glutathione in red blood cells |
| Changes in catalase activity in red blood cells | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | — |
| Changes in creatine kinase activity in serum | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | — |
| Changes in high sensitivity C-reactive protein in serum | Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise | — |
| Changes in white blood cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | — |
| Changes in adhesion molecule concentration in blood | Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise | Measurement of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular cell adhesion molecule-1 (sICAM-1) concentrations in plasma |
| Changes in cytokine concentration in serum | Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise, 8 days post-exercise | Measurement of interleukin-1β (IL-1β) and interleukin-6 (IL-6) |
| Changes in neutrophil count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of neutrophil count in blood |
| Changes in lymphocyte count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of lymphocyte count in blood |
| Changes in monocyte count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of monocyte count in blood |
| Changes in basophil count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of baseophil count in blood |
| Changes in eosinophil count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of eosinophil count in blood |
| Changes in T-helper cell count in blood | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Cytofluorometric analysis of T-helper cell count in blood |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in delayed onset of muscle soreness | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Assessment of the delayed onset of muscle soreness by palpation of the vastus lateralis and rectus femoris following a squat motion |
| Maximal aerobic capacity | One day before exercise | Assessment of maximal oxygen consumption |
| Body composition | One day before exercise | Measurement of body composition by Dual Emission X-ray Absorptiometry (DXA) |
| Changes in dietary intake profile | One day before exercise and daily for 8 consecutive days post-exercise | Assessment of dietary intake with emphasis on antioxidant element intake |
| Changes in muscle performance | Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise | Assessment of maximal knee extensor eccentric peak torque on an isokinetic dynamometer at 60o/s. |
Countries
Greece
Outcome results
None listed