AJP - Regulatory, Integrative and Comparative Physiology, Vol 255, Issue 5 839-R845, Copyright © 1988 by American Physiological Society
Immune activation and psychoneurogenic stress modulate corticosterone-releasing effects of lymphokines and ACTH
I. Torres-Aleman, I. Barasoain, J. Borrell and C. Guaza
Department of Psychobiology, Cajal Institute of Neurobiology, Madrid, Spain.
Possible modulatory effects of psychoneurogenic stress and
endotoxin-induced immune activation on the in vitro
corticosterone-releasing effects of lymphokine-containing supernatants
(LCS) and adrenocorticotropic hormone (ACTH) were studied in rats. We have
found that activation of the immune system by endotoxin increases the in
vitro sensitivity of the adrenocortical cells to LCS and ACTH. In addition,
we found that psychoneurogenic stress not only produced an increase of in
vitro adrenal sensitivity to ACTH, but it also enhanced the release of
corticosterone after perfusion of LCS. A synergistic interaction between
ACTH and LCS was observed in all experimental groups of animals studied. An
increased adrenal sensitivity to LCS and ACTH after stress or immune
activation might have a functional significance, since the adrenal cortex
is a major site in the response of the organism to alterations in the
homeostatic balance. On the other hand, the temporal pattern of in vitro
corticosterone release after LCS was different in all groups under study
compared with that observed after ACTH challenge. LCS elicited a more rapid
corticosterone response that lasted for a shorter time than after giving
ACTH. These latter results suggest that different mechanisms may underlie
the effects of LCS and ACTH on adrenal corticosteroidogenesis. In
conclusion, the present findings further reinforce the existence of
possible physiologically relevant interactions between the immune system
and the pituitary-adrenal axis.
