Effects of intraventricular norepinephrine and estradiol benzoate on weight regulatory behavior in female rats

Abstract

Ovariectomized female rats had 1 [mu]g estradiol benzoate (EB) or l-norepinephrine hydrochloride (NE:50, 100, 150, 250 [mu]g) administered into the right lateral ventricle. Both NE and EB stimulated activity whether infused in the light or in the dark. When given in the light EB and 50-150 [mu]g NE produced an increase in food consumption; when administered 1 h into the dark the drugs caused a drop in feeding. Pretreatment with 2.0 [mu]g phentolamine prevented the activity increase associated with EB or NE; imipramine potentiated the effects of both drugs. It was proposed that increased brain NE is sufficient to produce the increased locomotion and decreased feeding characteristic of the female rat in estrus.