title: Exercise regulation of intestinal tight junction proteins.
abstract: Gastrointestinal distress, such as diarrhoea, cramping, vomiting, nausea and gastric pain are common among athletes during training and competition. The mechanisms that cause these symptoms are not fully understood. The stress of heat and oxidative damage during exercise causes disruption to intestinal epithelial cell tight junction proteins resulting in increased permeability to luminal endotoxins. The endotoxin moves into the blood stream leading to a systemic immune response. Tight junction integrity is altered by the phosphoylation state of the proteins occludin and claudins, and may be regulated by the type of exercise performed. Prolonged exercise and high-intensity exercise lead to an increase in key phosphorylation enzymes that ultimately cause tight junction dysfunction, but the mechanisms are different. The purpose of this review is to (1) explain the function and physiology of tight junction regulation, (2) discuss the effects of prolonged and high-intensity exercise on tight junction permeability leading to gastrointestinal distress and (3) review agents that may increase or decrease tight junction integrity during exercise.
authors.affiliation: Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Micah
authors.initials: M
authors.lastname: Zuhl
authors.affiliation: Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Lanphere
authors.affiliation: Department of Nutrition/Dietetics, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Carole
authors.initials: C
authors.lastname: Conn
authors.affiliation: Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Karol
authors.initials: K
authors.lastname: Dokladny
authors.affiliation: Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Pope
authors.initials: P
authors.lastname: Moseley
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D016207:Cytokines / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005502:Food; D018882:Heat Stress Disorders / Q000503:physiopathology; D006360:Heat-Shock Proteins / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D007413:Intestinal Mucosa / Q000502:physiology; D007422:Intestines / Q000098:blood supply / Q000502:physiology*; D007511:Ischemia / Q000503:physiopathology; D010539:Permeability; D010766:Phosphorylation / Q000502:physiology; D062725:Tight Junction Proteins / Q000096:biosynthesis / Q000502:physiology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D016207:Cytokines; D006360:Heat-Shock Proteins; D062725:Tight Junction Proteins
keywords: Biochemistry; Nutrition; Physiology; Stress response to exercise and adaptations of stress proteins to exercise training