Hypothermia-enhanced splenic cytokine gene expression is independent of the sympathetic nervous system

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2006-09, Vol.291 (3), p.R558-R565
• Main Authors: Ganta, Chanran K, Helwig, Bryan G, Blecha, Frank, Ganta, Roman R, Cober, Richard, Parimi, Sujatha, Musch, Timothy I, Fels, Richard J, Kenney, Michael J
• Format: Article
• Language: English
• Subjects: Animals; Blood Pressure; Cytokines - genetics; Cytokines - metabolism; Gene Expression Regulation; Heart Rate; Hypothermia - metabolism; Rats; Rats, Inbred F344; Spleen - metabolism; Sympathetic Nervous System - physiology
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.00846.2005

1 Departments of Anatomy and Physiology and 2 Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas Submitted 5 December 2005 ; accepted in final form 31 January 2006 Splenic nerve denervation abrogates enhanced splenic cytokine gene expression responses to acute heating, demonstrating that hyperthermia-induced activation of splenic sympathetic nerve discharge (SND) increases splenic cytokine gene expression. Hypothermia alters SND responses; however, the role of the sympathetic nervous system in mediating splenic cytokine gene expression responses to hypothermia is not known. The purpose of the present study was to determine the effect of hypothermia on the relationship between the sympathetic nervous system and splenic cytokine gene expression in anesthetized F344 rats. Gene expression analysis was performed using a microarray containing 112 genes, representing inflammatory cytokines, chemokines, cytokine/chemokine receptors and housekeeping genes. A subset of differentially expressed genes was verified by real-time RT-PCR analysis. Splenic SND was decreased significantly during cooling (core temperature decreased from 38 to 30°C) in splenic-intact rats but remained unchanged in sham-cooled splenic-intact rats (core temperature maintained at 38°C). Hypothermia upregulated the transcripts of several genes, including, chemokine ligands CCL2, CXCL2, CXCL10, and CCL20, and interleukins IL-1 , IL-1 , and IL-6. Gene expression responses to hypothermia were similar for the majority of cytokine genes in splenic-intact and splenic-denervated rats. These results suggest that hypothermia-enhanced splenic cytokine gene expression is independent of splenic SND. hypothermia; splenic cytokine gene expression; splenic sympathetic nerve discharge Address for reprint requests and other correspondence: M. J. Kenney, Dept. of Anatomy and Physiology, Coles Hall 228, Kansas State Univ., 1600 Denison Ave., Manhattan, KS 66506 (e-mail: kenny{at}vet.k-state.edu )