Tricyclic antidepressants가 고양이 척수후각세포의 통각정보전달에 미치는 효과 = Studies on the Analgesic Effects of Tricyclic Antidepressants in the Anesthetized Cat

다국어 초록 (Multilingual Abstract)

To investigate effects of tricyclic antidepressants(TCAs) on the processing of the afferent inputs at the spinal cord level, the responses of wide dynamic range(WDR) cells to mechanical stimulation of the receptive field and to electrical stimulation of the isolated afferent nerve were recorded in the normal cats as well as in the spinalized animals. As an effort to elucidate the mechanism of action of TCA, effects of amitriptyline(AMIT), desipramine(DESI) and clomipramine(CLOM) were observed in the animals treated with naloxone(1mg/kg), cyprogeptadine(2mg/kg) nad yohimbine(100㎍/kg).
All the TCAs tested invariably ingibited the responses of WDR cells to mechanical or electrical stimulations. After intravenous administration of CLOM(7mg/kg) and DESI(6mg/kg). the responses to pinch and C-fiber stimulation, and ingibitory effects of these drugs lasted for more than 90 min. AMIT(6mg/kg) elicited only a small but significant ingibition of WDR cell responses to pinch and C-fiber stimulation, and these depressed responses were gradually restored almost to the control level in 60 min after durg administration. TCAs directly applied to the spinal cord did not show any significant influence on the activities of the WDR cells. On the other hand, inhibitory effects of TCAs on all the responses of WDR cells were almost completely abolished in the spinal animals. Following intravenous administration of naloxone or cyproheptadine, ingibitory effect of CLOM was partially blocked. Effect of DESI was completely antagonized by naloxone and partially by yohimbine.
These findings suggest that TCA-induced ingibition of WDR cell responses is mediated through the endogenous opioid and monoaminergic descending ingibitory control system.