AJP - Regulatory, Integrative and Comparative Physiology, Vol 257, Issue 3 661-R667, Copyright © 1989 by American Physiological Society

ARTICLES

Prior immobilization stress alters adrenal hormone responses to hemorrhage in rats

J. Graessler, R. Kvetnansky, D. Jezova, M. Dobrakovova and G. R. Van Loon
Institute of Pathological Biochemistry, Medical Academy, Carl-Gustav-Carus, Dresden, German Democratic Republic.

The effect of prior immobilization stress (IMO) on the plasma epinephrine (EPI), norepinephrine (NE), adrenocorticotropic hormone (ACTH), and corticosterone (CS) responses to acute hemorrhage was studied in conscious male rats with chronic catheters in tail artery, using two combinations of IMO and hemorrhage. IMO per se led to significant increases of EPI, NE, ACTH, and CS in all animals. Hemorrhage of 25% of estimated blood volume (EBV) performed immediately after 150 min IMO caused exaggerated release of EPI and NE, whereas CS remained unchanged at the level previously elevated by IMO. ACTH response to initial blood loss of 12.5% was diminished in previously immobilized rats. Hemorrhage of 35% EBV after 60 min IMO and a 10-min recovery period also resulted in potentiated increases in EPI and NE, suppressed ACTH secretion, and no further change in stress-elevated CS concentration. No differences between groups were observed in relative mean arterial blood pressure, plasma protein, and lactate responses to 35% hemorrhage. Posthemorrhagic increase of plasma concentration of several tissue enzyme activities was significantly higher in prestressed rats. Furthermore, 24-h mortality rate increased by 49%. In summary, our results indicate that prior IMO potentiated activation of the sympathoadrenomedullary system and suppressed ACTH response to subsequent hemorrhage. Altered neuroendocrine responsiveness and stress-induced prehemorrhagic tissue damage may play roles in the increased susceptibility of the organism to blood loss.

This article has been cited by other articles:

				R. Andres, O. Marti, and A. Armario Direct evidence of acute stress-induced facilitation of ACTH response to subsequent stress in rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 1999; 277(3): R863 - R868. [Abstract] [Full Text] [PDF]

				O. Marti, R. Andres, and A. Armario Defective ACTH response to stress in previously stressed rats: dependence on glucocorticoid status Am J Physiol Regulatory Integrative Comp Physiol, September 1, 1999; 277(3): R869 - R877. [Abstract] [Full Text] [PDF]

				K. Pacak, M. Palkovits, G. Yadid, R. Kvetnansky, I. J. Kopin, and D. S. Goldstein Heterogeneous neurochemical responses to different stressors: a test of Selye's doctrine of nonspecificity Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R1247 - R1255. [Abstract] [Full Text] [PDF]

				L. M. Romero, K. K. Soma, and J. C. Wingfield Hypothalamic-pituitary-adrenal axis changes allow seasonal modulation of corticosterone in a bird Am J Physiol Regulatory Integrative Comp Physiol, May 1, 1998; 274(5): R1338 - R1344. [Abstract] [Full Text] [PDF]