[Psychomotor excitation caused by beta-endorphin: effect of rubidium and lithium].

Effects of lithium and rubidium administered into the cerebral ventricles of conscious cats on psychomotor excitation produced by synthetic human beta-endorphin similarly injected have been investigated. Lithium, but not rubidium, prevented the psychomotor stimulation caused by beta-endorphin. Naloxone, applied intracerebroventricularly, also prevented the psychomotor stimulation produced by this polypeptide. It appears, therefore, that only lithium has a psychotherapeutic value when homeostatic neurohumoral mechanisms are disturbed in the central nervous system by a surplus of beta-endorphin.