Central serotoninmimetic action of phenylpiperazines.

Studies of 1-(m-chlorophenyl)-piperazine (m-CPP), 1-(p-chlorophenyl)-piperazine (p-CPP) and 1-phenylpiperazine (PP) were carried out on rats, mice and rabbits in order to assess their stimulatory effect on the central serotonin system. It was found out that m-CPP and p-CPP evoked a characteristic syndrome in the mouse behavior. All the phenylpiperazine derivatives stimulated the flexor reflex in the spinal rat and evoked hyperthermia in rats at a high ambient temperature (28 degrees C) and in rabbits. The above effects were abolished by cyproheptadine, a drug blocking the serotonin receptors. The obtained results indicate that the phenylpiperazine derivatives studied have a central serotoninmimetic action.