AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 5 1115-R1121, Copyright © 1992 by American Physiological Society
Influenza virus-induced changes in rabbit sleep and acute phase responses
M. Kimura-Takeuchi, J. A. Majde, L. A. Toth and J. M. Krueger
Department of Physiology, University of Tennessee, Memphis 38163.
Systematic investigations of sleep after viral inoculation have not
previously been described. In the present study, rabbits were inoculated
intravenously (iv) with control allantoic fluid followed by two sequential
inoculations of influenza virus at intervals of 24 h. After each i.v.
inoculation, sleep and brain temperature (Tbr), as well as leukocyte
distributions and serum levels of antiviral activity and ceruloplasmin,
were monitored. The first viral inoculation elicited several acute phase
responses, including increased non-rapid-eye-movement sleep (NREMS), Tbr,
serum antiviral activity, and serum ceruloplasmin levels, as well as
neutrophilia and lymphopenia. In contrast to the effects of the first
inoculation, after the second inoculation of virus, all these acute phase
parameters were diminished or absent (the hyporesponsive state).
Inoculation of naive rabbits with heat-inactivated virus was similarly
ineffective; however, inoculation of this group of rabbits with viable
virus 24 h later did induce full-scale acute phase responses. The possible
role of cytokines in mediating the acute phase response after influenza
viral challenge is discussed. Results support the hypothesis that sleep is
a facet of the acute phase response involved in host defense mechanisms.
