Combined hypervolemia and hypoosmolality alter hypothalamic-pituitary-adrenal axis response to endotoxin stimulation

Details

Serval ID
serval:BIB_02C0C05B4247
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Combined hypervolemia and hypoosmolality alter hypothalamic-pituitary-adrenal axis response to endotoxin stimulation
Journal
Neuroendocrinology
Author(s)
Dadoun  F., Velut  J. G., Guillaume  V., Sauze  N., Orsoni  J. C., Gaillard  R. C., Oliver  C. C.
ISSN
0028-3835 (Print)
Publication state
Published
Issued date
05/1999
Volume
69
Number
5
Pages
352-9
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May
Abstract
Changes in corticotropin (ACTH) and glucocorticoid secretion have been described during disturbances of body fluid homeostasis and attributed to alterations in arginine vasopressin (AVP) secretion from magnocellular hypothalamic neurons. In order to further characterize the mechanisms involved in the interactions between body fluid alterations and pituitary adrenal function, we manipulated osmolality and volemia in sheep under stimulation of the pituitary-adrenal axis by acute injection of endotoxin. We have recently shown that endotoxin injection induces a long-lasting release of both corticotropin releasing hormone (CRH) and AVP into hypophysial portal blood, and an early stimulation of AVP secretion into peripheral vessels, thus suggesting a joint activation of magnocellular and parvocellular neurons of the PVN. We used the same experimental model to investigate the effect of combined volume loading and plasma dilution (achieved by 1-deamino-8-D-arginine (dDAVP) administration together with infusion of 2 liters of 2.5% glucose solution) on CRH, AVP, ACTH and cortisol responses to endotoxin stimulation. In volume-loaded animals, ACTH and cortisol responses to endotoxin were significantly blunted and we observed a parallel decrease in portal CRH and jugular and portal AVP levels. These data show that hypoosmolality and/or hypervolemia reduce(s) ACTH and cortisol response to stress in sheep as in other species. They strongly suggest that this reduction in ACTH and cortisol responses to endotoxin involve not only magnocellular hypothalamic neurons secreting AVP, as usually assumed, but also PVN parvocellular neurons secreting both CRH and AVP.
Keywords
Adrenocorticotropic Hormone/blood Animals Arginine Vasopressin/blood Basal Nucleus of Meynert/cytology/drug effects/metabolism Blood Volume/*physiology Corticotropin-Releasing Hormone/blood Endotoxins/administration & dosage/*pharmacology Hydrocortisone/blood Hypothalamo-Hypophyseal System/drug effects/*physiology Injections, Intravenous Lipopolysaccharides/administration & dosage/pharmacology Male *Osmolar Concentration Pituitary-Adrenal System/drug effects/*physiology Sheep Stimulation, Chemical
Pubmed
Web of science
Create date
15/02/2008 16:57
Last modification date
20/08/2019 12:24
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