Intermittent footshock (FS) suppresses immune function of spleen cells. To determine
if the autonomic nervous system mediates this immunosuppression in spleen cells, we
tested whether cutting the splenic nerve, which depletes splenic norepinephrine levels
by 98-100% and eliminates catecholamine fibers, blocks the effects of stress. Splenic
nerve sections, sham operations, or no surgery were performed on male Sprague-Dawley
rats. Ten days later, rats were injected with sheep red blood cells (SRBC). Three
days later, rats were placed in a chamber equipped with a shock grid. Foot shock (1.6
mA) was administered for 5 s on a VI 3.5 min schedule for 60 min. Each FS was preceded
by a 15-s warning tone. Controls were treated identically except for the FS. The next
day spleen cells were harvested and the number of IgM plaque-forming cells (PFCs)
determined. For the sham and unoperated control animals, the number of PFCs was reduced
for the stressed animals relative to the nonstressed controls, and there was no effect
of the sham surgeries. In contrast, there was no difference between the stressed and
nonstressed groups in which the splenic nerve had been sectioned, and their PFC response
was comparable to the controls. Next we examined the effects of FS on the proliferative
response to mitogens (PHA and ConA) following splenic nerve sections or sham operations.
One week following surgery, animals were given a 60-min session of FS or exposed to
the chamber/tone without FS. Rats were then killed, spleens harvested, and the proliferative
response to mitogens determined.(ABSTRACT TRUNCATED AT 250 WORDS)