Activation and selectivity of splenic sympathetic nerve electrical
activity response to bacterial endotoxin.
Macneil, B. J., A. H. Jansen, A. H. Greenberg, and D. M. Nance.
Department of Pathology and Manitoba Institute of Cell Biology,
University of Manitoba, Winnipeg, Manitoba, Canada R3E 0W3
APStracts 2:0237R, 1995.
Regulatory interactions and neuroanatomical pathways have been
described between the sympathetic nervous system (SNS) and the immune
system. It is not clear whether these pathways are activated during
immune responses and if target specificity provides selective
regulation of immune organs. The present study examined whether
systemic injection of endotoxin (LPS) induces sympathetic outflow to
an immune organ (spleen). Adult male rats were used to record
sympathetic nerve activity from either the splenic or renal nerve
following i.v. injections of LPS. Splenic nerve activity increased in
a dose dependent manner up to 175% of control following injection of
LPS with an onset time of 17.1 to 23.5 minutes. In contrast, renal
nerve recordings showed a significantly slower onset time of 37.1 to
52.6 minutes at similar doses. In addition, splenic nerve recordings
of 8/8 rats responded to 10 [mu]g of LPS, whereas only 4/11 positive
renal nerve responses were observed at this dose. The magnitude of
the responses of both splenic and renal nerves were comparable. These
data suggest that the splenic nerve responds to and is more sensitive
to LPS-stimulated sympathetic activation in terms of latency and
frequency of responses. Thus, sympathetic outflow can be directed to
an immune organ in response a stimulus known to activate the immune
system.
Received 29 March 1995; accepted in final form 12 August 1995.
APS Manuscript Number R208-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 15 September 1995.