Abstract
Interleukin-8 (IL-8) is released in response to infection, inflammation, and trauma. The most important stimuli for IL-8 release during these pathological processes are IL-1, tumor necrosis factor, and bacterial lipopolysaccharide (endotoxin), factors that have been shown to suppress feeding. In the present study, the participation of IL-8 on the central regulation of feeding was investigated. Intracerebroventricular (icv) microinfusion of recombinant human IL-8 (rhIL-8, 1.0-100 ng/rat) suppressed the short-term (2-h) food intake. The most effective dose of rhIL-8, 20 ng, decreased 2-h food intake by 25% and nighttime food intake by 23%. Intracerebroventricular microinfusion of anti-rhIL-8 antibody (200 and 500 ng) blocked the effect of 20 ng rhIL-8 on 2-h and nighttime food intakes. Computerized analysis of behavioral patterns for the 2-h period demonstrated a specific reduction of meal size (by 33%), whereas meal frequency and meal duration were not affected after the icv microinfusion of 20 ng rhIL-8. This short-term food intake suppression by icv rhIL-8 was accompanied by a small, but significant, increase in cerebrospinal fluid-brain and rectal temperatures. Intraperitoneal administration of rhIL-8 in doses equivalent to those administered centrally had no effect on food intake. The results suggest that IL-8 acts directly in the central nervous system to decrease feeding. This effect of IL-8 may contribute to the food intake suppression frequently accompanying pathological processes.
Original language | English (US) |
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Pages (from-to) | R877-R882 |
Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
Volume | 265 |
Issue number | 4 part 2 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |
Keywords
- behavior
- cerebrospinal fluid
- cytokine
- feeding and drinking
- fever
- food and water intake
- growth factor
- hypothalamus
- immune system
- immunomodulator
- intracerebroventricular administration
- meal pattern
- nervous system
- neuroimmunology
- rat
ASJC Scopus subject areas
- Physiology