|
|
||||||||
Regulation of a number of aspects of the acute-phase response, including induction of fever and activation of the hypothalamo-pituitary-adrenal axis, occurs within the hypothalamus. The acute-phase response appears to be co-ordinated by the inflammatory cytokine interleukin-1 (IL-1). A number of studies using hybridization techniques to measure IL-1 gene expression and immunocyto-chemistry to localize immunoactive IL-1 have established the concept that the central nervous system, and in particular the hypothalamus, is a site of IL-1 production, and that levels increase in response to inflammatory stimuli. In this report we present data on the levels of IL-1β produced in the rat hypothalamus using quantitative immunoassay techniques. Bacterial endotoxin, administered to rats in vivo, evoked increases in hypothalamic IL-1β levels which were significant within 1 h, and reached maximum levels at 5–10 h. The response to endotoxin was dose-related, and levels reached in hypothalamic extracts corresponded to intra-hypothalamic levels of the order of 20 ng/ml. During short-term in-vitro culture of rat hypothalami, endotoxin stimulated a dose-related increase in both the synthesis and the secretion of IL-1β, which reached similar levels to those seen after in-vivo stimulation. Hypothalami obtained from animals stimulated with endotoxin in vivo did not, however, show any evidence of persistent stimulation of IL-1β production when subsequently cultured in vitro.
These data support the concept that production of hypothalamic IL-1 is an essential step in regulating the activity of the hypothalamus during the acute-phase response, and provide for the first time quantitative data on the magnitude, dose—response relationships and time-courses of rat hypothalamic IL-1β production in vivo and in vitro.
This article has been cited by other articles:
![]() |
D Kumar and R K Tandon Fatigue in cholestatic liver disease--a perplexing symptom Postgrad. Med. J., July 1, 2002; 78(921): 404 - 407. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. N. Luheshi, J. D. Gardner, D. A. Rushforth, A. S. Loudon, and N. J. Rothwell Leptin actions on food intake and body temperature are mediated by IL-1 PNAS, June 8, 1999; 96(12): 7047 - 7052. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Lang, J. Fan, M. M. Wojnar, T. C. Vary, and R. Cooney Role of central IL-1 in regulating peripheral IGF-I during endotoxemia and sepsis Am J Physiol Regulatory Integrative Comp Physiol, April 1, 1998; 274(4): R956 - R962. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. T. Nguyen, T. Deak, S. M. Owens, T. Kohno, M. Fleshner, L. R. Watkins, and S. F. Maier Exposure to Acute Stress Induces Brain Interleukin-1beta Protein in the Rat J. Neurosci., March 15, 1998; 18(6): 2239 - 2246. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. V. Turnbull, F. J. Pitossi, J.-J. Lebrun, S. Lee, J. C. Meltzer, D. M. Nance, A. del Rey, H. O. Besedovsky, and C. Rivier Inhibition of Tumor Necrosis Factor-alpha Action within the CNS Markedly Reduces the Plasma Adrenocorticotropin Response to Peripheral Local Inflammation in Rats J. Neurosci., May 1, 1997; 17(9): 3262 - 3273. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. V. Turnbull and C. Rivier Inhibition of Gonadotropin-Induced Testosterone Secretion by the Intracerebroventricular Injection of Interleukin-1{beta} in the Male Rat Endocrinology, March 1, 1997; 138(3): 1008 - 1013. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |