title: Bioenergetics of the aging heart and skeletal muscles: Modern concepts and controversies.
abstract: Age-related alterations in the bioenergetics of the heart and oxidative skeletal muscle tissues are of crucial influence on their performance. Until now the prevailing concept of aging was the mitochondrial theory, the increased production of reactive oxygen species, mediated by deficiency in the activity of respiratory chain complexes. However, studies with mitochondria in situ have presented results which, to some extent, disagree with previous ones, indicating that the mitochondrial theory of aging may be overestimated. The studies reporting age-related decline in mitochondrial function were performed using mainly isolated mitochondria. Measurements on this level are not able to take into account the system level properties. The relevant information can be obtained only from appropriate studies using cells or tissue fibers. The functional interactions between the components of Intracellular Energetic Unit (ICEU) regulate the energy production and consumption in oxidative muscle cells. The alterations of these interactions in ICEU should be studied in order to find a more effective protocol to decelerate the age-related changes taking place in the energy metabolism. In this article, an overview is given of the present theories and controversies of causes of age-related alterations in bioenergetics. Also, branches of study, which need more emphasis, are indicated.
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia. Electronic address: kersti.tepp@kbfi.ee.
authors.forename: Kersti
authors.initials: K
authors.lastname: Tepp
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Natalja
authors.initials: N
authors.lastname: Timohhina
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Marju
authors.initials: M
authors.lastname: Puurand
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Aleksandr
authors.initials: A
authors.lastname: Klepinin
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Chekulayev
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Igor
authors.initials: I
authors.lastname: Shevchuk
authors.affiliation: Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia; Faculty of Science, Tallinn University, Narva mnt. 25, 10120, Estonia.
authors.forename: Tuuli
authors.initials: T
authors.lastname: Kaambre
mesh_terms: D000375:Aging / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species
keywords: Creatine kinase; Energy metabolism; Energy transfer; Heart; Mitochondria; Skeletal muscle