Enhanced sensitivity to anorexia and consumption of drinking water induced by interleukin-1 beta in obese yellow mice.

Exogenously administered interleukin-1 beta (IL-1) was reported to suppress food intake and endogenous CRF in the brain was reported to be involved in mediating the IL-1-induced anorexia. The present study was undertaken to investigate the effect of IL-1 (i.p.) on food and water intake in obese yellow mice and in lean mice. Enhanced sensitivity to IL-1-induced suppression of food and water intake were observed in obese yellow mice compared to lean mice (food intake suppression: lean 29.92%, obese 88.48%; water intake suppression: lean 25.18%, obese 71.56% of respective controls). After treatment of the mice with ibuprofen (10 mg/kg i.p.), the suppression of food and water intake was prevented in lean mice but unaffected in obese mice. The results suggest that there may be differential sensitivity to activation of CRF neurons induced by the peripheral injection of IL-1 in obese yellow and in lean mice.