麻薬性鎮痛薬の脊髄レベルにおける鎮痛機序 ―その2オピエイトとモノアミン系の相互作用―
スポンサーリンク
概要
- 論文の詳細を見る
This study was carried out in order to investigate the interaction between opiate receptor subtypes and monoamines (alpha 2 adrenergic agonist and serotonin) at the level of the spinal cord. Extracellular activity of a single wide dynamic range (WDR) neurons in the spinal dorsal horn which was evoked by radiant heat stimulus (51℃) was recorded in decerebrate, spinally transected cats. In the first study, we examined the synergism between an opiate and alpha 2 adrenergic agonist, clonidine, to identify the subtypes of the opiate that were likely to be involved in such synergistic suppression of noxiously evoked activity of a WDR neuron. Spinally administered ineffective dosage of morphine (25μg), DADL (delta/mu agonist, 20μg) and DPDPE (selective delta agonist, 30μg) combined with ineffective dosage of clonidine (5μg) produced the significant synergistic suppression of evoked WDR neuronal activity. However, ineffective and effective dosage of DAGO (selective mu agonist, 1 and 1.5μg, respectively) did not show ny synergistic action with clonidine. The synergism between morphine and clonidine was reversed by intravenous selective delta antagonist ICI174, 864. In the second study, the synergism between morphine and serotonin was examined. Ineffective and effective dosage of serotonin (250 and 500μg, respectively) combined with an ineffective dosage of morphine produced only additive suppression, but not synergistic suppression. In the third study, we investigated the existence of cross-antagonism between the opiate and monoamines systems. There was no cross-antagonism reactivity; neither naloxone nor ICI174, 864 was able to reverse the suppression of clonidine or serotonin, and alpha 2 adrenergic antagonist, yohimbine, was not able to reverse the suppression of opiates. These results indicate that opiates interact at the spinal delta receptors to produce a synergistic interaction of suppressing evoked WDR neuronal activity with spinal clonidine, but not serotonin. It also demonstrates that opiates and monoamines act directly on the opiate and monoamine receptors, respectively.
- 1990-10-01
論文 | ランダム
- 成長期児童の下肢柔軟性と体格との関係
- オゾンによる枯草菌の殺菌
- 側鎖に複素環 (窒素) 骨格を導入したモノテルペニル誘導体の合成とその生理活性 : 生理活性物質の合成に関する研究(第17報)
- 枯草菌による生物防除のメカニズム
- 蛋白質工学的手法による枯草菌プロテアーゼ・サチライシンの機能変換に関する研究