Aphagic and adipsic effects of interleukin-1

Intake of rat chow and water was reduced 4 and 8 h after the intrahypothalamic injection of 5 ng interleukin-1a (IL-1a). Although core body temperature was also elevated significantly for at least 4 h by the administration of this cytokine, resting energy expenditure was not altered. These results suggest that IL-1a may be involved in the reduction of feeding associated with trauma, infection or cancer, by inducing early satiety. Additionally, hyperthermia associated with the injection of IL-1a appears to be maintained by decreased heat dissipation rather than by increased thermogenesis.