title: Whey protein supplementation accelerates satellite cell proliferation during recovery from eccentric exercise.
abstract: Human skeletal muscle satellite cells (SCs) are essential for muscle regeneration and remodeling processes in healthy and clinical conditions involving muscle breakdown. However, the potential influence of protein supplementation on post-exercise SC regulation in human skeletal muscle has not been well investigated. In a comparative human study, we investigated the effect of hydrolyzed whey protein supplementation following eccentric exercise on fiber type-specific SC accumulation. Twenty-four young healthy subjects received either hydrolyzed whey protein + carbohydrate (whey, n = 12) or iso-caloric carbohydrate (placebo, n = 12) during post-exercise recovery from 150 maximal unilateral eccentric contractions. Prior to and 24, 48 and 168 h post-exercise, muscle biopsies were obtained from the exercise leg and analyzed for fiber type-specific SC content. Maximal voluntary contraction (MVC) and serum creatine kinase (CK) were evaluated as indices of recovery from muscle damage. In type II fiber-associated SCs, the whey group increased SCs/fiber from 0.05 [0.02; 0.07] to 0.09 [0.06; 0.12] (p < 0.05) and 0.11 [0.06; 0.16] (p < 0.001) at 24 and 48 h, respectively, and exhibited a difference from the placebo group (p < 0.05) at 48 h. The whey group increased SCs/myonuclei from 4 % [2; 5] to 10 % [4; 16] (p < 0.05) at 48 h, whereas the placebo group increased from 5 % [2; 7] to 9 % [3; 16] (p < 0.01) at 168 h. MVC decreased (p < 0.001) and muscle soreness and CK increased (p < 0.001), irrespective of supplementation. In conclusion, whey protein supplementation may accelerate SC proliferation as part of the regeneration or remodeling process after high-intensity eccentric exercise.
authors: Section of Sport Science, Department of Public Health, Aarhus University, Dalgas Avenue 4, 8000, Aarhus, Denmark, jean@ph.au.dk.
authors: Jean
authors: J
authors: Farup
authors: Stine Klejs
authors: SK
authors: Rahbek
authors: Inge Skovgaard
authors: IS
authors: Knudsen
authors: Frank
authors: F
authors: de Paoli
authors: Abigail L
authors: AL
authors: Mackey
authors: Kristian
authors: K
authors: Vissing
mesh_terms: D000328:Adult; D049109:Cell Proliferation; D003402:Creatine Kinase / Q000097:blood; D018592:Cross-Over Studies; D004032:Diet; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006868:Hydrolysis; D007150:Immunohistochemistry; D007537:Isometric Contraction; D008297:Male; D008894:Milk Proteins / Q000737:chemistry*; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism; D009132:Muscles / Q000502:physiology*; D051763:PAX7 Transcription Factor / Q000378:metabolism; D012038:Regeneration; D013997:Time Factors; D000067816:Whey Proteins; D055815:Young Adult
chemical_list: D008894:Milk Proteins; D051763:PAX7 Transcription Factor; C497321:PAX7 protein, human; D000067816:Whey Proteins; D003402:Creatine Kinase