title: Physiological and molecular correlates of age-related changes in the human beta-adrenergic receptor system.
abstract: Aging decreases hormone responsiveness in several receptor systems. In this article I consider both physiological and biochemical studies supporting the hypothesis that beta-adrenergic receptor responsiveness is reduced with aging in humans. Reduced chronotropic and vasodilator responses to the beta-receptor agonists isoproterenol and metaproterenol have been demonstrated. In human leukocytes a reduction in adenylate cyclase (EC 4.6.1.1) activity occurs with aging. More recently it has been suggested that this reduction in beta-adrenergic responsiveness with aging may be caused by an uncoupling of the beta receptor from the catalytic component.
mesh_terms: D000375:Aging; D000242:Cyclic AMP / Q000096:biosynthesis; D006321:Heart / Q000503:physiopathology; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000378:metabolism / Q000502:physiology*
chemical_list: D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP