Abstract

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.

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Publisher Full Text

Authors

Perez SD, Kozic B, Molinaro CA, Thyagarajan S, Ghamsary M, Lubahn CL, Lorton D, Bellinger DL

Institution

Department of Physiology & Pharmacology, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA.

Source

Journal of neuroimmunology 247:1-2 2012 Jun 15 pg 38-51

MeSH

Adrenergic alpha-Agonists
Adrenergic beta-Agonists
Aging
Analysis of Variance
Animals
Body Weight
Catecholamines
Chromatography, High Pressure Liquid
Cyclic AMP
Dose-Response Relationship, Drug
Male
Norepinephrine
Organ Size
Oxazoles
Propanolamines
Protein Binding
Random Allocation
Rats
Rats, Inbred F344
Rats, Sprague-Dawley
Receptors, Adrenergic, beta
Spleen
Sympathetic Nervous System
Time Factors

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

22546498