东莨菪碱抑制呼吸效应及其机制

INHIBITORY EFFECT AND MECHANISM OF SCOPOLAMINE ON RESPIRATION

本文给兔侧脑室、犬椎动脉以及静脉注射东莨菪碱，从呼吸频率、潮气量、通气量及血气分析多项指标皆观察到东莨菪碱有明显呼吸抑制作用，且存在剂量依赖关系。东莨菪碱尚能拮抗毛果芸香碱的呼吸兴奋效应，但不能拮抗６β－乙酰氧基去甲托烷呼吸抑制效应，反而起协同作用。上述结果提示东莨菪碱引起呼吸抑制可能与阻断呼吸中枢Ｍ１受体有关。

In conscious rabbits, dogs and anaesthetized dogs,the respiratory frequency (FR), tidal volume (Vt) and minute ventilation (Vm) were determined in order to confirm whether the respiratory effect of scopolamine is stimulatory or inhibitory. Arterial blood samples were taken intermittently and analyzed for Po2, Pco2 and pH. When scopolamine was injected icy, ia and iv, the decrease of FR, Vt, Vm and Po2 and the increase of Pco2 were observed in two animals. When the drug was given in clinical doses used for treating respiratory failure, the effect was seen still observable. The results indicate that scopolamine inhibits respiration. Moreover, it was observed that excitatory effect of pilocarpine on respiration can be antagonized by scopolamine, but the inhibitory effect of 6β-acetoxy nortropane can not be antagonized, on the contrary, can be coordinated. The above results suggest that respiratory inhibition induced by scopolamine may be related to blocking M1-R of the respiratory center.