Chronically lowering sympathetic activity protects sympathetic nerves in spleens from aging F344 rats.
In the present study, we investigated how increased sympathetic tone during middle-age affects the splenic sympathetic neurotransmission. Fifteen-month-old (M) F344 rats received rilmenidine (0, 0.5 or 1.5mg/kg/day, i.p. for 90 days) to lower sympathetic tone. Controls for age were untreated 3 or 18M rats. We report that rilmenidine (1) reduced plasma and splenic norepinephrine concentrations and splenic norepinephrine turnover, and partially reversed the sympathetic nerve loss; and (2) increased β-adrenergic receptor (β-AR) density and β-AR-stimulated cAMP production. Collectively, these findings suggest a protective effect of lowering sympathetic tone on sympathetic nerve integrity, and enhanced sympathetic neurotransmission in secondary immune organs.
Department of Physiology & Pharmacology, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA.
SourceJournal of neuroimmunology 247:1-2 2012 Jun 15 pg 38-51
Analysis of Variance
Chromatography, High Pressure Liquid
Dose-Response Relationship, Drug
Rats, Inbred F344
Receptors, Adrenergic, beta
Sympathetic Nervous System
Pub Type(s)Journal Article
Research Support, N.I.H., Extramural