Satellite cell pool size expansion is affected by skeletal muscle characteristics

Abstract

The purpose of this study was to determine the change of satellite cells (SC) pool size after an acute bout of strenuous exercise and to determine whether this is affected by baseline SC count and fiber type.Participants completed 40min (5 × 8 bouts, 2 min rest) downhill running (DHR) at 80% VO2max at −10% gradient. Muscle biopsy was taken a week before VO2max test and 7–9 days after DHR. Delayed onset muscle soreness (DOMS) and creatine kinase activities (CK) were measured on d1, d2 d7, and d9 after the DHR bout. Satellite cells were analyzed with Pax7 and laminin immunohistochemistry staining.DOMS and CK increased 1 day after DHR (P < 0.01) and returned to baseline. SC pool size was increased by 26% 7–9 days after the exercise intervention (P = 0.005). SC count after the acute exercise intervention was significantly correlated with VO2max (P = 0.03). A trend was seen in correlation between change in SC and percentage MHC type II (P = 0.10).This study reports that 7–9 days after a single bout of DHR, the SC pool expands and the expansion extent is associated with inter‐individual physiological characteristics: VO2max and with a tendency, skeletal muscle fiber type.Grant Funding Source : Claude Leon Foundation, NRF (National Research Foundation)