樟柳碱对呼吸中枢的影响

Effects of anisodine on respiratory center

给大鼠iv或icv M-受体阻滞剂樟柳碱,可引起膈神经放电节率加快,吸气与呼气时程缩短,每次放电脉冲数减少。免iv或闩部给樟柳碱,出现延髓孤束核区吸气相关神经元放电节率及膈神经放电节率同步加快。氧化震颤素能拮抗樟柳碱加快膈神经放电节率的作用。樟柳碱还能部分拮抗吗啡所致的膈神经放电节率减慢作用。

Anisodine (Ani), a new selective M receptor blocking agent, was isolated from Scopolia tangutica in China. The structure of Ani is similar to scopolamine. Ani (2.5, 5 mg·kg-1 iv, or 0. 6 mg·kg-1 icv) increased the rate of phrenic nerve discharges (PND), while the time of inspiration and expiration, and the spikes in each PND were reduced in urethan - anesthetized rats . In urethan -anethetized rabbits, Ani (2. 5 mg·kg-1 iv, or 0. 2 mg·kg-1 applied onto obex) increased the rate of PND. In tubocurarine-pretreated and artificially ventilated rabbits , Ani (2.5 mg ·kg-1 iv, or 0. 2 mg·kg-1 applied onto obex) increased the rate of inspiratory neurone firing in nucleus tractus solitariua. Oxotremorine (40 μg·kg-1 iv) antagonized the Am effects. Ani (2. 5 mg·kg-1 iv) partially antagonized the respiratory depression induced by morphine. These results provide the evidence that Ani stimulates the respiratory center through cholinergic M pathway and there may be some neuronal interaction between cholinergic and opiate receptors in the control of respiratory center.