Activity-wheel running blunts suppression of splenic natural killer cell cytotoxicity after sympathectomy and footshock.
We used chemical sympathectomy by 6-hydroxydopamine (6-OHDA) to examine whether adaptation by the sympathetic nervous system (SNS) is a plausible explanation for our prior finding that activity-wheel running blunts the suppression of splenic natural killer cell cytotoxicity after footshock. Male Fischer rats were assigned to treatments using a group (activity wheel vs. sedentary)x treatment (6-OHDA vs. saline)x condition (footshock vs. no shock) design. After 5-6 weeks, rats were injected i.p. with saline or with 40, 80, and 80 mg/kg 6-OHDA on pre experimental days -5, -3, and -1. Half the rats received 6 min of random footshock during a 40-min period. Cytotoxicity was determined by standard 4-h 51Cr release assay. Sympathectomy reduced splenic [NE] by 72%. After 6-OHDA injection and footshock, percent lysis was 33% lower in sedentary rats compared with activity-wheel runners and home-cage controls, p=0.048. The results suggest that activity-wheel running leads to adaptations that offset an altered SNS modulation of splenic NK cell cytotoxicity in response to footshock.
Dishman
R K
RK
Department of Exercise Science, The University of Georgia, 30602-6554, Athens, GA, USA. rdishman@coe.uga.edu
Hong
S
S
Soares
J
J
Edwards
G L
GL
Bunnell
B N
BN
Jaso-Friedmann
L
L
Evans
D L
DL
D000818:Animals; D001835:Body Weight; D003602:Cytotoxicity, Immunologic / Q000502:physiology*; D004597:Electroshock; D005528:Foot; D007694:Killer Cells, Natural / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D013154:Spleen / Q000502:physiology*; D013562:Sympathectomy
D009638:Norepinephrine