The effect of piribedil on body temperature in mice and rats

Piribedil produces a pronounced hypothermia both in mice and rats. This hypothermia was prevented by previous administration of dopamine receptor blocking agents (spiperone in mice and rats, pimozide in mice), tricyclic antidepressant drugs (imipramine, clomipramine, desipramine) in mice and LSD in rats. Administration of agents acting on serotonin receptors (cyproheptadine, p-chlorophenylalanine) or of a classical anticholinergic drug, atropine, did not change the hypothermizing effect of piribedil in rats. Thus, the hypothermia produced by piribedil is apparently similar to that produced by apomorphine. The possibility of a secondary stimulation of serotonergic receptors through direct stimulatory action of piribedil on dopamine neurons is discussed.