Central administration of a nitric oxide precursor abolishes both the hypothalamic serotonin release and the hypophagia induced by interleukin-1β in obese Zucker rats

The results suggest that, in obese Zucker rats, activation of the serotonergic system in the medial hypothalamus participates in IL-1β-induced anorexia. Since l-arginine, probably through NO stimulation, abolished both the anorexia and the serotonergic activation, it can be proposed that the NO system, either directly or indirectly, counteracts IL-1β anorexia. The hypothalamic serotonergic system is likely to mediate this NO effect.