Cytokines stimulate the CRH but not the vasopressin neuronal system: evidence for a median eminence site of interleukin-6 action
Details
Serval ID
serval:BIB_A5F98B5B1E05
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Cytokines stimulate the CRH but not the vasopressin neuronal system: evidence for a median eminence site of interleukin-6 action
Journal
Neuroendocrinology
ISSN
0028-3835 (Print)
Publication state
Published
Issued date
07/1992
Volume
56
Number
1
Pages
46-53
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jul
Research Support, Non-U.S. Gov't --- Old month value: Jul
Abstract
Antigen-activated immune cells acutely release cytokines which, besides their effects on the immune system, increase hypothalamopituitary-adrenocortical (HPA) function to counteract the inflammatory process. The present study was designed to test, using in vitro paradigms, whether there exists a hypothalamic and/or a median eminence site of action, whereby different substances derived from the immune system could stimulate the CRH and/or the arginine-vasopressin (AVP) neuronal pathway. For this purpose, whole medial basal hypothalamus (containing the median eminence) were dissected from female rats and incubated in vitro with several concentrations of interleukin-1 (IL-1)beta, interleukin-6 (IL-6), tumor necrosis factor (TNF)-alpha, thymosin fraction 5 (TF5) or bacterial lipopolysaccharide (LPS). After a 40-min incubation period, the amounts of CRH and AVP released into the incubation medium were measured by specific radioimmunoassays (RIAs). Additional experiments were carried out by superfusing isolated rat median eminence fragments with the different test substances; CRH and AVP released into the medium were also measured by RIAs. The results indicated that IL-1 beta (10(-11) to 10(-7) M), IL-6 (0.06 x 10(-10) to 0.4 x 10(-10) M), TNF-alpha (6 x 10(-9) to 6 x 10(-7) M) and TF5 (5-500 micrograms/ml) but not LPS (1-100 ng/ml) significantly enhanced hypothalamic CRH secretion above baseline in a concentration-related fashion. Additionally, superfusion experiments demonstrated that, among all test substances, only IL-6 possesses a direct and dose-dependent CRH-releasing activity at the median eminence level. Conversely, no preparation enhanced basal AVP release in either in vitro design.(ABSTRACT TRUNCATED AT 250 WORDS)
Keywords
Angiotensin II/pharmacology
Animals
Arginine Vasopressin/metabolism
Corticotropin-Releasing Hormone/*physiology/secretion
Cytokines/*pharmacology
Female
Hypothalamus/metabolism
Hypothalamus, Middle/metabolism
Interleukin-6/*pharmacology
Lipopolysaccharides
Median Eminence/*drug effects
Neurons/*physiology
Potassium/pharmacology
Rats
Rats, Inbred Strains
Thymosin/analogs & derivatives/pharmacology
Vasopressins/*physiology
Pubmed
Web of science
Create date
15/02/2008 17:57
Last modification date
20/08/2019 16:11