Interferon produces hyperthermic responses in rats.

The effects of administration of alpha human leukocyte interferon into the anterior hypothalamic preoptic area on metabolic, respiratory and vasomotor activities, as well as body temperatures, were assessed in unanesthetized rats at various ambient temperatures (Ta). Intrahypothalamic administration of interferon produced dose-dependent fever in rats at Ta = 8-30 degrees C. The interferon-induced fever was due to increased metabolism and/or cutaneous vasoconstriction (or decreased heat loss). Furthermore, the fever induced by interferon was antagonized by pretreatment of animals with indomethacin, an inhibitor of prostaglandin synthesis. The data indicate that the fever induced by intrahypothalamic interferon is due to the endogenous release of prostaglandins in the anterior hypothalamic preoptic area of rat's hypothalamus.