title: Organ-specific physiological responses to acute physical exercise and long-term training in humans.
abstract: Virtually all tissues in the human body rely on aerobic metabolism for energy production and are therefore critically dependent on continuous supply of oxygen. Oxygen is provided by blood flow, and, in essence, changes in organ perfusion are also closely associated with alterations in tissue metabolism. In response to acute exercise, blood flow is markedly increased in contracting skeletal muscles and myocardium, but perfusion in other organs (brain and bone) is only slightly enhanced or is even reduced (visceral organs). Despite largely unchanged metabolism and perfusion, repeated exposures to altered hemodynamics and hormonal milieu produced by acute exercise, long-term exercise training appears to be capable of inducing effects also in tissues other than muscles that may yield health benefits. However, the physiological adaptations and driving-force mechanisms in organs such as brain, liver, pancreas, gut, bone, and adipose tissue, remain largely obscure in humans. Along these lines, this review integrates current information on physiological responses to acute exercise and to long-term physical training in major metabolically active human organs. Knowledge is mostly provided based on the state-of-the-art, noninvasive human imaging studies, and directions for future novel research are proposed throughout the review.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku and Turku University Hospital, Turku, Finland; Department of Cardiology, Division of Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands ilkka.heinonen@utu.fi.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Heinonen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland;
authors.forename: Kari K
authors.initials: KK
authors.lastname: Kalliokoski
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland;
authors.forename: Jarna C
authors.initials: JC
authors.lastname: Hannukainen
authors.affiliation: Department of Cardiology, Division of Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Duncker
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Department of Medicine, University of Turku and Turku University Hospital, Turku, Finland; and.
authors.forename: Pirjo
authors.initials: P
authors.lastname: Nuutila
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland;
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000222:Adaptation, Physiological; D000273:Adipose Tissue / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism; D004064:Digestive System / Q000378:metabolism; D004734:Energy Metabolism; D015444:Exercise; D006801:Humans; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D012039:Regional Blood Flow; D013997:Time Factors
chemical_list: D010100:Oxygen