The anorectic effect of neurotensin is mediated via a histamine H ₁ receptor in mice

Neurotensin (NT), a tridecapeptide found in the mammalian brain and peripheral tissues, induces a decrease in food intake after central administration. In this investigation, we examine whether the histaminergic system is involved in NT-induced suppression of feeding. Intracerebroventricular injection of NT (0.1-1 nmol/mouse) led to dose-dependent inhibition of food intake in fasted ddY mice. The anorectic effect induced by NT (0.1 nmol/mouse) was ameliorated upon co-administration of pyrilamine (3 nmol/mouse), an antagonist for histomine H ₁ receptor. The NT-induced anorectic effect was partially ameliorated in H ₁ knockout mice. The findings suggest that the H ₁ receptor in part mediates the NT-induced suppression of food intake.