Time-Course Changes of Hormones and Cytokines by Lipopolysaccharide and Its Relation with Anorexia
We assessed the time course effects of lipopolysaccaride (LPS) on food intake, cytokines, and hormones in rats and evaluated the relation between LPS-induced anorexia and its possible causative factors. Food intake was reduced 2h after LPS injection (500μg/kg, intraperitoneally) and remained decreas...
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Published in | Journal of Physiological Sciences Vol. 57; no. 3; pp. 159 - 165 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | Japanese |
Published |
The Physiological Society of Japan
2007
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Online Access | Get full text |
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Summary: | We assessed the time course effects of lipopolysaccaride (LPS) on food intake, cytokines, and hormones in rats and evaluated the relation between LPS-induced anorexia and its possible causative factors. Food intake was reduced 2h after LPS injection (500μg/kg, intraperitoneally) and remained decreased for 24h. Plasma TNF-α and IL-6 levels increased by LPS administration at 0.5 and 2h, and at 2 and 4h, respectively. Plasma leptin and glucose levels were elevated at 8 and 16h, and insulin levels were elevated at 2, 4, 8, and 16h in the LPS-injected group, as compared to the counterpart controls. IL-6 levels in the CSF were elevated at 2 and 4h. Hypothalamic cytokines tended to increase as early as 0.5h after LPS injection and remained increased until 16h. LPS-induced anorexia was attenuated in insulin-deficient STZ rats and was abolished by insulin treatment. The hypothalamic expression of NPY, a target of insulin's anorexic effect, was decreased 2h after LPS administration, and central NPY injection (3nM) prevented LPS-induced anorexia. In conclusion, cytokines, insulin, and leptin levels evidence different time courses by LPS administration. In LPS-induced anorexia, insulin may constitute a newly found causative factor, whereas leptin appears to be uninvolved in an early period in rats. |
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ISSN: | 1880-6546 1880-6562 |