Possible role of central interleukins on the anorexigenic effect of lipopolysaccharide in chicks.

1. The purpose of the present study was to determine if central interleukin-1β (IL1β), interleukin-6 (IL6) and interleukin-8 (IL8) affect feeding behaviour in chicks (Gallus gallus) and examine if central interleukins are related to the lipopolysaccharide (LPS)-induced anorexia. 2. Intra-abdominal (IA) injection of LPS significantly suppressed feeding behaviour and significantly increased mRNA expression of IL1β and IL8 in the diencephalon when compared to the control group, while IL6 tended to be increased. 3. Intracerebroventricular (ICV) injection of 200 ng IL1β significantly decreased food intake at 60 min after the injection while IL6 and IL8 had no effect. 4. IA injection of these ILs (200 ng) had no effect on food intake in chicks. 5. ICV injection of 200 ng IL1β did not affect water intake and plasma corticosterone concentration, suggesting that central IL1β might not be related to the regulation of drinking behaviour and the hypothalamus-pituitary-adrenal axis. 6. The present study demonstrated that central IL1β but not IL6 and IL8 might be related to the inhibition of feeding in chicks.