title: β-adrenergic receptor responsiveness in aging heart and clinical implications.
abstract: Elderly healthy individuals have a reduced exercise tolerance and a decreased left ventricle inotropic reserve related to increased vascular afterload, arterial-ventricular load mismatching, physical deconditioning and impaired autonomic regulation (the so called "β-adrenergic desensitization"). Adrenergic responsiveness is altered with aging and the age-related changes are limited to the β-adrenergic receptor density reduction and to the β-adrenoceptor-G-protein(s)-adenylyl cyclase system abnormalities, while the type and level of abnormalities change with species and tissues. Epidemiological studies have shown an high incidence and prevalence of heart failure in the elderly and a great body of evidence correlate the changes of β-adrenergic system with heart failure pathogenesis. In particular it is well known that: (a) levels of cathecolamines are directly correlated with mortality and functional status in heart failure, (b) β1-adrenergic receptor subtype is down-regulated in heart failure, (c) heart failure-dependent cardiac adrenergic responsiveness reduction is related to changes in G proteins activity. In this review we focus on the cardiovascular β-adrenergic changes involvement in the aging process and on similarities and differences between aging heart and heart failure.
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy ; "S. Maugeri" Foundation, Scientific Institute of Telese Terme (BN), IRCCS Telese Terme, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Ferrara
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Klara
authors.initials: K
authors.lastname: Komici
authors.affiliation: Department of Medicine and Health Sciences, University of Molise Campobasso, Italy.
authors.forename: Graziamaria
authors.initials: G
authors.lastname: Corbi
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Gennaro
authors.initials: G
authors.lastname: Pagano
authors.affiliation: "S. Maugeri" Foundation, Scientific Institute of Telese Terme (BN), IRCCS Telese Terme, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Furgi
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy ; "S. Maugeri" Foundation, Scientific Institute of Telese Terme (BN), IRCCS Telese Terme, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Rengo
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Grazia D
authors.initials: GD
authors.lastname: Femminella
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Leosco
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II" Naples, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Bonaduce
keywords: G-protein coupled receptor kinase; aging heart; exercise; failing heart; β-adrenergic receptors; β-adrenoceptor desensitization; β-adrenoceptor down-regulation