AJP - Regulatory, Integrative and Comparative Physiology, Vol 258, Issue 2 393-R397, Copyright © 1990 by American Physiological Society
Diazepam inhibits stimulating effect of cooling preoptic area on antibody production
M. Banet and S. Brandt
Institute for Normal and Pathological Physiology, Philipps University, Marburg, Federal Republic of Germany.
To clarify the mechanism of the stimulating effect of fever on the primary
antibody response, rats were immunized with sheep erythrocytes, and a
fever-like response was induced by cooling the preoptic area for five days.
Diazepam, 0.5 mg/kg, given daily during the cooling time, did not affect
the normal antibody response of the control animals nor did it prevent the
rise in body temperature elicited by cooling the preoptic area but it did,
nevertheless, strongly reduce the stimulating effect of this procedure on
antibody production. A smaller reduction of this effect was also seen in
adrenalectomized rats in which a physiological and stable plasma level of
corticosterone was maintained. Because diazepam suppresses some sympathetic
and endocrine responses to stress, these data suggest that the effect of
cooling the preoptic area on the primary antibody response, and, by
inference, that of fever, is to a large extent mediated by the adrenal and
other stress response or responses to the cold stimulus. The results do
not, however, exclude the possibility of an additional, direct effect of
the elevated body temperature on immunocompetent cells.
