open access

https://hdl.handle.net/2115/50801

Effect of triiodothyronine (T3) augmentation of acute milnacipran administration on monoamine levels: an in vivo microdialysis study in rats

英語

triiodothyronine

2012-10

Dove Medical Press

Neuropsychiatric Disease and Treatment

2012(8)

501-507

Background: Up to 30% of depressed patients are partially or totally resistant to antidepressant therapy. The administration of triiodothyronine (T3) to antidepressant nonresponders can be an effective augmentation strategy, although the mechanism is not fully understood. Methods: In vivo microdialysis was used to examine the effect of T3 augmentation of the antidepressant, milnacipran. Basal extracellular serotonin, norepinephrine, and dopamine levels were measured before and after acute milnacipran administration in the medial prefrontal cortex and amygdala of rats which had received subchronic (7 days) T3 treatment or control saline. Results: Subchronic administration of T3 at 0.1 mg/kg significantly increased basal extracellular levels of serotonin in the medial prefrontal cortex, but not in the amygdala. In contrast, subchronic administration of T3 at 0.2 mg/kg did not alter basal extracellular serotonin levels in the medial prefrontal cortex. Basal extracellular levels of norepinephrine and dopamine were not modified by either dose of T3 in either region. Acute administration of milnacipran, a serotonin-norepinephrine reuptake inhibitor, to control animals resulted in a significant increase of extracellular levels of serotonin, norepinephrine, and dopamine. When administered to animals treated subchronically with T3 at 0.1 mg/kg, milnacipran produced an additional increase in extracellular serotonin levels but not in levels of norepinephrine or dopamine in the medial prefrontal cortex of rats. Conclusion: These results suggest that the mechanism of the augmentation effect of milnacipran by T3 administration occurs via enhancement of serotonergic neurotransmission, but not through noradrenergic or dopaminergic neurotransmission.

学術雑誌論文

Version of Record

1176-6328