백서 강제수영모델의 부동시간 단축에 미치는 항우울제의 개선 효과에 대한 도파민 및 노르아드레날린계 약물의 영향

Effect of Dopaminergic and Noradrenergic Drugs on the Reduction of Immobility Time Induced by Antidepressants in Forced Swimming Test in Rats

Depression had been known to be mainly abnormalities of noradrenergic or serotonergic neurotransmission in the past. But recently some reports showed that depression results from abnormalities of interaction of complex neurotransmitters， reemphasifing the role of dopaminergic system in depression. Objective ： This study was designed to investigate the role of dopaminergic neurotransmission in the action of tricyclic antidepressants. Method ： Rats were repeatedly treated with a variety of tricyclic antidepressants for 7 days, i.e. desipramine, amitriptyline, amineptine and haloperidol(dopamine antagonist), propranolol (adrenergic blocker), bromocriptine(dopamine agonist). The reduction of immobilization time by drugs in forced swimming test was measured on the assumption that reduction of immobilization time suggests antidepressive effect. Results ： 1) Desipramine had the strongest antidepressive action, partially through dopaminergic neurotransmission and partially through noradrenergic neurotransmission. 2) Amitriptyline and amineptine had weaker antidepressive action than desipramine, mainly through dopaminergic neurotransmission. 3) Bromocriptine had the weakest antidepressive action than the above 3 antidepressants but had partial antidepressive action. Conclusion ： These results suggest that mechanisms of action of tricyclic antidpressants include dopaminergic neurotransmission and dopamine agonist has partial antidepressive action.