P物质感觉神经对呼吸道平滑肌张力和血管通透性的调解作用

REGULATIVE EFFECTS OF SP SNESORY NREVE FIBRES ON THE SMOOTH MUCLE TENSION AND VESSEL PERMEABILITY OF GUINEA PIG RESPIRATORY TRACT

电场刺激豚鼠离体主支气管和肺门支气管引起长时程收缩反应。此收缩反应对阿托品、六甲双胺和苯海拉明不敏感,可被TTX所消除。P物质拮抗剂对此电场刺激所引起的收缩反应有显著的抑制作用。逆向刺激麻醉豚鼠双侧颈迷走神经引起吹气压升高,气管伊文氏兰含量增加,心率减慢和血压下降。这些反应对苯海拉明和六甲双胺不敏感。阿托品完全消除刺激迷走神经引起的血压下降和心率减慢。但只部分影响吹气压升高和伊文氏兰渗出增加。P物质拮抗剂显著抑制刺激迷走神经引起的吹气压升高和伊文氏兰渗出增加。这些结果提示,迷走神经源性P物质感觉神经纤维对呼吸道平滑肌张力和血管通透性发挥着重要调解作用。

Electrical field stimulation ( EFS ) of guinea pig main and hilus bronchi induced long lasting contractions in vitro, which were unsensitive to atropine, hexamethonium and phenoxybenzamine.TTX abolished the contractile responses completely.A substance p antagonist obviously in hibited the contraction induced by EFS.antistiumlation of bilateral cervical vagi of anesthetized guinea pig elicited sharp elevation cf respira tory insufflation pressure and increased Evans blue extravasation in the (?)achea, which was accompanied by a bradycardia and hypotension. After atropine and hexameth onium pretreatment, the cardiovascular effects of vagus nerve stimulation were abolished, but had no obvious inhibition to the increases in insufflation pressure and in Evans blue extravasation. The substance P antagonist inhibit ed the increase in insufflation pressure and in Evans b; ue extravasation ov erwhelmingly.These results suggest that SP sensory nerve fibres originating from vagi possess important regulative effects on the respiratory smooth mu scle tension and vessel permeability.