Endocrinology, Vol 116, 633-639, Copyright © 1985 by Endocrine Society

ARTICLES

Evidence for multifactor regulation of the adrenocorticotropin secretory response to hemodynamic stimuli

PM Plotsky, TO Bruhn and W Vale

We have examined the contributions of corticotropin-releasing factor (CRF), arginine vasopressin (AVP), epinephrine, and oxytocin to the ACTH secretory responses to hemorrhage. The relative significance of each of these putative ACTH regulatory factors is undefined with respect to net ACTH secretion. Initially, the effects of selective systemic pharmacological blockade of individual factors on the ACTH response were examined. Immunoneutralization of CRF reduced resting ACTH levels below the detection limits of our RIA and abolished the secretory response to hemorrhage. Ganglionic blockade or treatment with a potent AVP antagonist reduced the ACTH secretory response by 55% and 38%, respectively. Further evidence for multifactor regulation of hemodynamically evoked alterations in ACTH secretion was obtained by measurement of the concentrations of these factors in the hypophysial portal circulation during hemorrhage. Immunoreactive CRF, AVP, oxytocin and epinephrine were present in the portal plasma at concentrations within a range shown to evoke ACTH secretion from cultured pituitary cells when presented alone or in combination. The concentrations of all of these were significantly elevated during hemorrhage. During atrial pulsation, a stimulus mimicking volume loading and associated with a reduction of systemic ACTH levels, we observed a significant decline in portal concentrations of immunoreactive AVP coupled with a nonsignificant trend toward reduced portal immunoreactive CRF levels. These observations are highly suggestive of multifactor regulatory control of ACTH secretion in response to hemodynamic stimuli.

This article has been cited by other articles:

				K. Pacak and M. Palkovits Stressor Specificity of Central Neuroendocrine Responses: Implications for Stress-Related Disorders Endocr. Rev., August 1, 2001; 22(4): 502 - 548. [Abstract] [Full Text] [PDF]

				D. Engler, E. Redei, and I. Kola The Corticotropin-Release Inhibitory Factor Hypothesis: A Review of the Evidence for the Existence of Inhibitory as Well as Stimulatory Hypophysiotropic Regulation of Adrenocorticotropin Secretion and Biosynthesis Endocr. Rev., August 1, 1999; 20(4): 460 - 500. [Abstract] [Full Text] [PDF]

				S. M. Tanimura, G. Sanchez-Watts, and A. G. Watts Peptide Gene Activation, Secretion, and Steroid Feedback during Stimulation of Rat Neuroendocrine Corticotropin-Releasing Hormone Neurons Endocrinology, September 1, 1998; 139(9): 3822 - 3829. [Abstract] [Full Text] [PDF]

				S. M. Tanimura and A. G. Watts Corticosterone Can Facilitate as Well as Inhibit Corticotropin-Releasing Hormone Gene Expression in the Rat Hypothalamic Paraventricular Nucleus Endocrinology, September 1, 1998; 139(9): 3830 - 3836. [Abstract] [Full Text] [PDF]

				R Sapolsky, C Rivier, G Yamamoto, P Plotsky, and W Vale Interleukin-1 stimulates the secretion of hypothalamic corticotropin-releasing factor Science, October 23, 1987; 238(4826): 522 - 524. [Abstract] [PDF]

				F Berkenbosch, J van Oers, A del Rey, F Tilders, and H Besedovsky Corticotropin-releasing factor-producing neurons in the rat activated by interleukin-1 Science, October 23, 1987; 238(4826): 524 - 526. [Abstract] [PDF]