Effects of tricyclic antidepressants on tetrabenazine-induced depletion of brain monoamines in rats. 1. Norepinephrine

Repetitive administration of tetrabenazine induces irreversible changes in locomotion and morphology of the substantia nigra in rats

We investigated the effects of a 7 day repetitive administration of tetrabenazine (TBZ), which depletes monoamines, on both locomotor behavior and histomorphometrial findings of substantia nigra in rats. These results were compared with the effects of a single dose of TBZ, which is a common paradigm in animal models of depression. A single dose of TBZ causes reversible decrease of voluntary movement and no histological changes. In contrast, as for repetitive administration, this experiment demonstrated irreversible and significant decrease in spontaneous locomotion, as well as histological changes in the neurons of the substantia nigra pars compacta. These results have led us to propose that prolonged TBZ administration could provide a novel and useful model for the behavioral characteristics and anatomical pathology of Parkinson's disease as one of the oxidative stress models induced by abnormal dopamine metabolism.

TJS-010, a new prescription of oriental medicine, antagonizes tetrabenazine-induced suppression of spontaneous locomotor activity in rats

1. The authors have determined the effect of TJS-010, a new prescription of oriental medicine, on the locomotor activity in rats. 2. Tetrabenazine(TBZ) decreased the spontaneous locomotion in rats, and attenuated the contents of amines and increased their metabolism in various regions in rat brain. 3. TJS-010 inhibited the locomotor suppression induced by TBZ: however, neither amine contents nor their metabolism was not altered, which suggested that TJS-010 postsynaptically modulated the transmission or transduction. 4. Imipramine also inhibited the decrease in locomotion induced by TBZ. 5. These results suggest a possibility that TJS-010 has an antidepressive effect.