title: Gender differences on the effects of aging on cardiac and peripheral adrenergic stimulation in old conscious monkeys.
abstract: We examined the effects of gender and aging on cardiac and peripheral hemodynamic responses to beta-adrenergic receptor (beta-AR) stimulation in young (male = 5.9 +/- 0.4 yr old and female = 6.5 +/- 0.7 yr old) and old (male = 19.8 +/- 0.7 yr old and female = 21.2 +/- 0.2 yr old) conscious monkeys (Macaca fascicularis), chronically instrumented for measurements of left ventricular (LV) and arterial pressures as well as cardiac output. Baseline LV pressure, the first derivative of LV pressure (LV dP/dt), cardiac index, mean arterial pressure, total peripheral resistance (TPR), and heart rate in conscious monkeys were not different among the four groups. Increases in LV dP/dt in response to 0.1 microg/kg isoproterenol (Iso) were diminished (P < 0.05) in old males (+99 +/- 11%) compared with young males (+194 +/- 18%). In addition, the inotropic responses to norepinephrine (NE) and forskolin (FSK) were significantly depressed (P < 0.05) in old males. Iso-induced reductions of TPR were less (P < 0.05) in old males (-28 +/- 2%) than in young males (-49 +/- 2%). The changes of TPR in response to NE and FSK were also significantly attenuated (P < 0.05) in old males. However, the LV dP/dt responses to BAY y 5959 (15 microg. kg-1. min-1), a Ca2+ channel promotor independent of beta-AR signaling, were not significantly different between old and young males. In contrast to results in male monkeys, LV dP/dt and TPR responses to Iso, NE, and FSK in old females were similar to those observed in young females. Thus both cardiac contractile and peripheral vascular dynamic responses to beta-AR stimulation are preserved in old female but not old male monkeys. This may explain, in part, the reduced cardiovascular risk in the older female population.
authors.affiliation: Dept. of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, PO Box 1709, 185 S. Orange Avenue, Medical Science Bldg., G609, Newark, NJ 07101-1709, USA.
authors.forename: Gen
authors.initials: G
authors.lastname: Takagi
authors.forename: Kuniya
authors.initials: K
authors.lastname: Asai
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Vatner
authors.forename: Raymond K
authors.initials: RK
authors.lastname: Kudej
authors.forename: Franco
authors.initials: F
authors.lastname: Rossi
authors.forename: Athanasios
authors.initials: A
authors.lastname: Peppas
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Takagi
authors.forename: Ranillo R G
authors.initials: RR
authors.lastname: Resuello
authors.forename: Filipinas
authors.initials: F
authors.lastname: Natividad
authors.forename: You-Tang
authors.initials: YT
authors.lastname: Shen
authors.forename: Dorothy E
authors.initials: DE
authors.lastname: Vatner
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D003243:Consciousness; D004095:Dihydropyridines / Q000494:pharmacology; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008252:Macaca fascicularis; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010053:Ovary / Q000166:cytology; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012727:Sex Characteristics; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D013566:Sympathomimetics / Q000494:pharmacology
chemical_list: C109289:BAY y 5959; D004095:Dihydropyridines; D011943:Receptors, Adrenergic, beta; D013566:Sympathomimetics; D005576:Colforsin; D007545:Isoproterenol; D009638:Norepinephrine