Central interleukin-1 beta enhances splenic sympathetic nerve activity in rats.
The central administration of immune cytokines such as interleukin-1 (IL-1) and interferon-alpha (IFN-alpha) results in the suppression of peripheral cellular immunity, which depends, at least partly, on the sympathetic nervous activity. An intrathird cerebroventricular (I3V) infusion of recombinant human IL-1 beta (rhIL-1 beta) (1-5 ng/rat) elicited a dose-dependent increase in the electrical activity of the splenic sympathetic nerve in urethane and alpha-chloralose anesthetized rats. The effect of rhIL-1 beta (1 ng/rat) was completely blocked by pretreatment with an IL-1 receptor antagonist (1 microgram/rat, I3V 10 min before rhIL-1 beta), sodium salicylate (1 microgram/rat), or alpha-melanocyte stimulating hormone (alpha-MSH) (400 ng/rat). Furthermore, an antagonist of corticotropin-releasing factor (CRF), alpha-helical CRF9-41 (2 micrograms/rat), completely abolished the rhIL-1 beta-induced increase in the splenic nerve activity, although an I3V infusion of CRF (1 microgram/rat) excited it. These results suggest that IL-1 beta in the brain activates splenic sympathetic activity by its receptor-mediated and prostaglandin-dependent action that is sensitive to alpha-MSH, depending on CRF system. Our findings, together with the previous results, suggest that the splenic sympathetic nerve represents one of the communication channels from the brain to the immune system.
Ichijo
T
T
Department of Physiology, Faculty of Medicine, Kyushu University 60, Fukuoka, Japan.
Katafuchi
T
T
Hori
T
T
D000704:Analysis of Variance; D000818:Animals; D002552:Cerebral Ventricles; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004525:Efferent Pathways / Q000187:drug effects; D007263:Infusions, Parenteral; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000494:pharmacology*; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000494:pharmacology; D012980:Sodium Salicylate / Q000494:pharmacology; D013154:Spleen / Q000187:drug effects / Q000294:innervation*; D013564:Sympathetic Nervous System / Q000187:drug effects*; D000521:alpha-MSH / Q000494:pharmacology
D007375:Interleukin-1; D010446:Peptide Fragments; D011994:Recombinant Proteins; D000521:alpha-MSH; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41); D012980:Sodium Salicylate