title: Myosin Light Chain Kinase (MLCK) Gene Influences Exercise Induced Muscle Damage during a Competitive Marathon.
abstract: Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin producing increases in force development during skeletal muscle contraction. It has been suggested that MLCK gene polymorphisms might alter RLC phosphorylation thereby decreasing the ability to produce force and to resist strain during voluntary muscle contractions. Thus, the genetic variations in the MLCK gene might predispose some individuals to higher values of muscle damage during exercise, especially during endurance competitions. The aim of this investigation was to determine the influence of MLCK genetic variants on exercise-induced muscle damage produced during a marathon. Sixty-seven experienced runners competed in a marathon race. The MLCK genotype (C37885A) of these marathoners was determined. Before and after the race, a sample of venous blood was obtained to assess changes in serum myoglobin concentrations and leg muscle power changes were measured during a countermovement jump. Self-reported leg muscle pain and fatigue were determined by questionnaires. A total of 59 marathoners (88.1%) were CC homozygotes and 8 marathoners (11.9%) were CA heterozygotes. The two groups of participants completed the race with a similar time (228 ± 33 vs 234 ± 39 min; P = 0.30) and similar self-reported values for fatigue (15 ± 2 vs 16 ± 2 A.U.; P = 0.21) and lower-limb muscle pain (6.2 ± 1.7 vs 6.6 ± 1.8 cm; P = 0.29). However, CC marathoners presented higher serum myoglobin concentrations (739 ± 792 vs 348 ± 144 μg·mL-1; P = 0.03) and greater pre-to-post- race leg muscle power reduction (-32.7 ± 15.7 vs -21.2 ± 21.6%; P = 0.05) than CA marathoners. CA heterozygotes for MLCK C37885A might present higher exercise-induced muscle damage after a marathon competition than CC counterparts.
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Juan
authors.identifier: http://orcid.org/0000-0002-5785-984X
authors.initials: J
authors.lastname: Del Coso
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Valero
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lara
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Salinero
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Gallo-Salazar
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Areces
mesh_terms: D000328:Adult; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology*; D063806:Myalgia / Q000235:genetics* / Q000503:physiopathology; D009219:Myosin-Light-Chain Kinase / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012420:Running
chemical_list: D009219:Myosin-Light-Chain Kinase