Effect of extended sleep deprivation on tumor growth in rats.
Bergmann, Bernard M., Allan Rechtschaffen, Marcia A. Giililand, and
Jose Quintans.
Departments of Psychiatry and Pathology, University of Chicago,
Chicago, Illinois, U.S.A.
APStracts 3:0228R, 1996.
To assess the effect of chronic sleep deprivation on host defense, we
observed growth and regression of a subdermal allogenic carcinoma
(Walker 256 rat tumor) in rats undergoing ten days of total sleep
deprivation (TSD rats), yoked stimulus control (TSC) rats that were
partially sleep deprived, and home cage control (HCC) rats. Tumor
size was measured daily. Integrated tumor size was smaller in TSD
rats than in both TSC (p = 0.04) and HCC rats (p = 0.0003). Thus host
defense against these tumors (as defined by reduction in tumor size)
was improved by sleep deprivation. This improvement could be a non
-specific effect, e.g. tumor growth can be inhibited by a catabolic
state (dietary restriction). TSD and TSC rats lost body weight,
indicating a catabolic state. However, tumor size was not predicted
by body weight change, but was predicted by change in sleep time (p
=0.02). Host defense enhancement could alternatively result from
enhanced immune response. Early tumor size (5 days) was similar in
the three groups, but peaked sooner in TSD rats than in both TSC (p =
0.05) and HCC rats (p = 0.01), leading to large differences in size
later. Immune suppressed rats also showed little difference from HCC
rats in early growth but large differences later. Thus host defense
in an in vivo model which manifests a systemic immune response can be
enhanced by sleep deprivation with timing which is consistent with an
enhancement of the immune response.
Received 28 September 1995; accepted in final form 6 June 1996.
APS Manuscript Number R616-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96