Clonidine-induced hyperphagia in monkeys: evidence for alpha 2-noradrenergic receptor mediation

The mechanism of clonidine-induced hyperphagia and weight gain in monkeys was studied in 11 Stumptail macaques. Clonidine induced a significant increase in food intake over baseline levels and a significant weight gain after the 3-day treatment period. Both changes induced by clonidine were antagonized by the alpha 2-noradrenergic antagonist yohimbine, but not by prazosin, an alpha 1-noradrenergic antagonist. These results suggest that clonidine-induced hyperphagia and weight gain in monkeys are mediated through alpha 2-noradrenergic receptors.