Peripherally administered 5-hydroxytryptamine elicits the full behavioural sequence of satiety

If 5-HT acts as a peripheral satiety signal, then it should not only produce anorectic effects when administered systemically but should allow the normal behavioural sequence of satiety to develop. Food-deprived rats treated with 5 mg/kg 5-HT were found to show, when given access to food, the full normal behavioural sequence of satiety, although the sequence occurred earlier than in rats treated with saline. It is therefore argued that 5-HT must be considered as a likely candidate for a peripheral satiety signal.