Abstract
Increased levels of β2-microglobulin (part of the class I major histocompatibility complex molecules) in body fluids are associated with activation of the immune system and pathophysiological processes. Various anorexigenic cytokines, including interferon-γ and tumor necrosis factor- α, induce the expression of class I molecules. Therefore, it is possible that β2-microglobulin may participate in the feeding suppression induced by cytokines or may have direct effects on feeding. In the present study, the effects of β2-microglobulin on the central regulation of feeding were investigated. Intracerebroventricular (ICV) microinfusion of β2- microglobulin (0.01-5.0 μg/rat) suppressed the nighttime food intake dose dependently. The most effective dose of β2-microglobulin, 5.0 μg/rat, decreased nighttime feeding by 38% and total daily food intake by 28%. Computerized analysis of behavioral patterns demonstrated that β2- microglobulin decreased meal size and meal frequency during the initial 4-h interval, but decreased only meal size during the second 4-h interval after the ICV microinfusion of 5.0 μg β2-microglobulin/rat; meal duration was not significantly affected in any interval. For the complete nighttime period, only meal size was significantly decreased. Cerebrospinal fluid- brain and rectal temperatures did not change significantly. ICV microinfusion of heat-treated β2-microglobulin or intraperitoneal administration of β2- microglobulin, in doses equivalent to those administered centrally, had no effect on food intake. The results suggest that β2-microglobulin may act centrally to decrease feeding, and this effect may participate in the anorexia frequently accompanying pathological processes.
Original language | English (US) |
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Pages (from-to) | R1513-R1519 |
Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
Volume | 268 |
Issue number | 6 37-6 |
State | Published - Jan 1 1995 |
Keywords
- behavior
- cerebrospinal fluid
- cytokine
- feeding and drinking
- food and water
- growth factor
- immune system
- immunomodulator
- intake
- intracerebroventricular administration
- nervous system
- neuroimmunology
- rat
ASJC Scopus subject areas
- Physiology
- Physiology (medical)