Hepatic vagus does not mediate IL-1 alpha induced anorexia.

Peripherally infused interleukin-alpha (IL-1 alpha) reduces food intake. Since the innervated liver modulates eating activity via the vagus, we investigated the role of the hepatic vagus in the etiology of IL-1 alpha induced anorexia. Ten male Fischer 344 rats were randomly assigned to hepatic vagotomy (HX-IL-1 group) or sham operation (Sham-IL-1 group), and an internal jugular catheter was inserted in all rats. Another six sham operated rats receiving normal saline i.v. throughout the study period served as general controls. After a 10-day recovery period, HX-IL-1 and Sham-ILI-1 rats were infused with 3 micrograms day-1 of IL-1 alpha for 3 days, followed by a 4 day infusion of saline. During the IL-1 alpha infusion, food intake was reduced at a similar rate and by a similar amount in both vagotomized and sham-operated rats. When IL-1 alpha infusion was stopped, food intake normalized at a similar rate in both HX-ILI-1 and Sham-IL-1 groups. These data indicate that the hepatic vagus is not involved in the etiology of IL-1 alpha induced anorexia.