Redox Status and Immune Function

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.

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.

orally in three daily dosages, content: 500 mL drink that contained water (375 mL), sugar-free cordial (125 ml), and 2 g of low-calorie glucose/dextrose powder

Measurement of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular cell adhesion molecule-1 (sICAM-1) concentrations in plasma

Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise, 8 days post-exercise

Assessment of the delayed onset of muscle soreness by palpation of the vastus lateralis and rectus femoris following a squat motion

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.

Department of Diabetes and Metabolism Unit of the Department of Clinical Therapeutics, National and Kapodistrian University of Athens