Central administration of ibuprofen failed to block the anorexia induced by interleukin-1.

Interleukins are synthesized by inflammatory cells and are thought to be involved in the anorexia associated with severe infection. In the present study, the possible involvement of prostaglandins in the anorexia caused by interleukin-1 was investigated. Recombinant human interleukin-1 beta (IL-1 beta). 17 ng/rat, injected into the third cerebroventricles significantly suppressed food intake and reduced the body weight gain in rats deprived of food for 18 h. Central administration of ibuprofen (IBP, 5-500 microgram/rat), a selective cyclooxygenase blocker, failed to attenuate the feeding suppression and body weight loss induced by IL-1 beta injection, although central administration of 50 microgram IBP blocked the increase of body temperature caused by central IL-1 beta. The data obtained suggest that a peripheral prostaglandin synthesizing system may play an important role in the anorexia caused by IL-1 beta.