Leptin facilitates histamine release from the hypothalamus in rats

We studied the effect of leptin on the release of histamine from the anteri or hypothalamus using an in vivo microdialysis in anesthetized rats. Histam ine release was significantly increased by leptin administration (1.3 mg/kg , i.p.) and kept at a high level for 4 h after the injection. The same dose of leptin significantly reduced food intake in another group of rats. This finding suggests that leptin activates the histaminergic system in the hyp othalamus, which may contribute the expression of leptin-induced anorectic effect. (C) 2000 Elsevier Science B.V. All rights reserved.