家兔延髓面神经后核内侧区在吗啡抑制呼吸中的作用

THE ROLE OF THE MEDIAL AREA OF NUCLEUS RETROFACIALIS IN MORPHINE-INDUCED RESPIRATORY INHIBITION IN RABBITS

实验在麻醉、切断颈迷走神经、肌肉麻痹和人工通气的家兔上进行。静脉注射吗啡4mg/kg能显著地抑制呼吸,主要是使呼吸频率降低和每分钟膈神经活动减少。如果先向延髓面神经后核内侧区(mNRF)注射1μg/1μl纳洛酮,可大部分阻断静脉注射吗啡引起的呼吸抑制。向一侧mNRF注射10μg/1μl吗啡能显著地抑制呼吸,两侧注射则产生呼吸暂停。先向两侧mNRF注射1μg/1μl纳洛酮,可完全阻断mNRF注射吗啡引起的呼吸抑制。结果说明mNRF存在阿片受体,并在静脉注射吗啡引起的呼吸抑制中起重要作用。本工作还为mNRF在发生和维持呼吸节律中的重要作用提供了新的证据。

Experiments were performed on anaesthetized, vagotomized, paralyzed and artificially ventilated rabbits. Morphine (4mg/kg, i.v.) caused marked respiratory inhibition, mainly reduced respiratory rate and phrenic minute activity. The respiratory depression effect of morphine was almost blocked by pretreatment with naloxone (1μg / 1μl) injected into the medial area of the nucleus retrofacialis (mNRF). Respiratory depression was also induced by unilateral microinjection of morphine (10μg / 1μl) into mNRF, and bilateral microinjection resulted in apnea in all animals. This effect could be fully prevented by injection of naloxone (1μg/ 1μl) into mNRF in advance. These data demonstrate that there are opiate receptors in the mNRF and they might take an important part in respiratory inhibition induced by systemic administration of morphine. The results support the hypothesis that the mNRF plays an important role in the genesis and maintenance of basic respiratory rhythm.