title: Effects of age and gender on the cardiovascular responses to isoproterenol.
abstract: We studied the effects of age and gender on cardiovascular responses to beta-adrenergic stimulation with the use of two-dimensional echocardiography in 16 young (aged 20-31) and 20 older (aged 60-75) healthy individuals. Following administration of atropine, each subject was given an infusion of isoproterenol at incremental doses from 0.010 to 0.030 microgram kg-1 min-1. The slopes of the fractional shortening-end-systolic wall stress (FS-sigma es) relationships were steeper in the young men (-0.87 +/- 0.28, n = 8) compared to the older men (-0.41 +/- 0.13, n = 10), and in the young women (-0.55 +/- 0.14, n = 8) compared to the older women (-0.38 +/- 0.13, n = 10). Furthermore, the magnitude of the age-associated differences in these slopes was larger in the men (old vs young) than in the women (old vs young) which, in the absence of changes in preload, suggests a greater decline in the contractile response to isoproterenol with advancing age in men compared to women. Furthermore, the men exhibited a greater attenuation of chronotropic response to isoproterenol than did the women. These observations suggest that gender plays a significant role in the age-associated decline in inotropic and chronotropic responses to beta-adrenergic stimulation, with men exhibiting a greater decline with aging than women.
authors.affiliation: Division of Geriatrics and Gerontology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Turner
authors.forename: C M
authors.initials: CM
authors.lastname: Mier
authors.forename: R J
authors.initials: RJ
authors.lastname: Spina
authors.forename: K B
authors.initials: KB
authors.lastname: Schechtman
authors.forename: A A
authors.initials: AA
authors.lastname: Ehsani
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002319:Cardiovascular System / Q000187:drug effects*; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D018721:Muscarinic Agonists / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D012727:Sex Characteristics; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D000318:Adrenergic beta-Agonists; D018721:Muscarinic Agonists; D007545:Isoproterenol