title: Treadmill exercise induces neutrophil recruitment into muscle tissue in a reactive oxygen species-dependent manner. An intravital microscopy study.
abstract: Intense exercise is a physiological stress capable of inducing the interaction of neutrophils with muscle endothelial cells and their transmigration into tissue. Mechanisms driving this physiological inflammatory response are not known. Here, we investigate whether production of reactive oxygen species is relevant for neutrophil interaction with endothelial cells and recruitment into the quadriceps muscle in mice subjected to the treadmill fatiguing exercise protocol. Mice exercised until fatigue by running for 56.3±6.8 min on an electric treadmill. Skeletal muscle was evaluated by intravital microscopy at different time points after exercise, and then removed to assess local oxidative stress and histopathological analysis. We observed an increase in plasma lactate and creatine kinase (CK) concentrations after exercise. The numbers of monocytes, neutrophils, and lymphocytes in blood increased 12 and 24 hours after the exercise. Numbers of rolling and adherent leukocytes increased 3, 6, 12, and 24 hours post-exercise, as assessed by intravital microscopy. Using LysM-eGFP mice and confocal intravital microscopy technology, we show that the number of transmigrating neutrophils increased 12 hours post-exercise. Mutant gp91phox-/- (non-functional NADPH oxidase) mice and mice treated with apocynin showed diminished neutrophil recruitment. SOD treatment promoted further adhesion and transmigration of leukocytes 12 hours after the exercise. These findings confirm our hypothesis that treadmill exercise increases the recruitment of leukocytes to the postcapillary venules, and NADPH oxidase-induced ROS plays an important role in this process.
authors.affiliation: Laboratório de Resolução da Resposta Inflamatória, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Albená
authors.initials: A
authors.lastname: Nunes-Silva
authors.affiliation: Laboratório de Resolução da Resposta Inflamatória, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Priscila T T
authors.initials: PT
authors.lastname: Bernardes
authors.affiliation: Laboratório de Resolução da Resposta Inflamatória, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Bárbara M
authors.initials: BM
authors.lastname: Rezende
authors.affiliation: Laboratório de Resolução da Resposta Inflamatória, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Lopes
authors.affiliation: Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Elisa C
authors.initials: EC
authors.lastname: Gomes
authors.affiliation: Laboratório de Imunobiofotônica, Departamento de Morfologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Pedro E
authors.initials: PE
authors.lastname: Marques
authors.affiliation: Laboratório de Endocrinologia e Metabolismo, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Paulo M A
authors.initials: PM
authors.lastname: Lima
authors.affiliation: Laboratório de Endocrinologia e Metabolismo, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Cândido C
authors.initials: CC
authors.lastname: Coimbra
authors.affiliation: Laboratório de Imunobiofotônica, Departamento de Morfologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Gustavo B
authors.initials: GB
authors.lastname: Menezes
authors.affiliation: Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Mauro M
authors.initials: MM
authors.lastname: Teixeira
authors.affiliation: Laboratório de Resolução da Resposta Inflamatória, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pinho
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000166:cytology* / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D000098:Acetophenones; D017382:Reactive Oxygen Species; D019344:Lactic Acid; C056165:acetovanillone; D003402:Creatine Kinase