溴化异丙托品和沙丁胺醇舒张气管平滑肌叠加作用的离体研究

Combined effects of salbutamol and ipratropium bromide on relaxing tracheal muscle in vitro

目的 :体外比较单用及合用溴化异丙托品和沙丁胺醇对乙酰胆碱、组胺、氯化钾诱导的离体豚鼠气管条收缩作用的影响。方法 :用溴化异丙托品孵育前后组胺、乙酰胆碱、KCl诱发的豚鼠离体气管条的收缩 ;用沙丁胺醇孵育前后组胺、KCl诱发的豚鼠离体气管条的收缩 ;溴化异丙托品和沙丁胺醇合用对组胺、乙酰胆碱和KCl诱导的豚鼠气管条收缩的影响。结果 :乙酰胆碱、组胺诱导离体豚鼠气管条收缩 ,呈典型的剂量反应效应 ,pD2 (达到 5 0 %最大反应的激动剂浓度 )分别为 5 .97± 0 .2 1,6 .4 8± 0 .5 4,用溴化异丙托品孵育后 ,其量效曲线压低 ,pD′2 (拮抗剂效价强度 )分别为 7.99± 0 .34,7.37± 0 .36 ;加用沙丁胺醇后 ,其量效曲线进一步压低。组胺10 -8mol·L-1引起豚鼠气管条收缩 ,10 -4mol·L-1达最大反应 ,pD2 为 6 .6 0± 0 .70 ;用沙丁胺醇孵育后 ,其量效曲线压低 ,pD′2 为 6 .0 6± 0 .2 7。加用溴化异丙托品 6× 10 -8mol·L-1孵育后 ,其量效曲线明显压低 (P <0 .0 1)。氯化钾 6 0mmol·L-1诱导气管条收缩 ,溴化异丙托品和沙丁胺醇抑制其收缩 ,其IC50(抑制 5 0 %最大反应的拮抗剂浓度 )分别为 4 .78×10 -6,3.18× 10 -6mol·L-1。两者合用 ,其抑制作用明显增强 (P <0 .0 1)。结论 :溴化异丙托品和沙丁胺?

AIM: To study the effects of ipratropium bromide (IB) with and without salbutamol (Sal) on the contraction of guinea pig tracheal strips induced by acetylcholine, histamine and potassium chloride in vitro. METHODS: The contraction of guinea pig tracheal strips induced by His, ACh and KCl before and after being incubated with ipratropium bromide; the contraction of guinea pig tracheal strips induced by His, and KCl before and after being incubated with salbutamol; the inhibitory effect of ipratropium bromide with salbutamol on the contraction of guinea pig tracheal strips induced by histamine and KCl. RESULTS: ACh ( 0.01 -1 mmol·L -1 ) caused concentration dependent contractions of tracheal strips and the resulting concentration response curve was classical, the values of pD 2 were 5.97 ± 0.21 , 6.48 ± 0.54 , respectively. IB depressed the concentration response curve with pD′ 2 values of 7.99 ± 0.34 and 7.37 ± 0.36 , respectively. After adding Sal, the curve was further depressed. His ( 0.01 μmol·L -1 ) caused the contraction of tracheal strips and its maximal response was obtained in 0.1 mmol·L -1 , the pD 2 value was 6.60 ± 0.70 . After incubated with Sal, the concentration response curve was depressed, and the pD′ 2 value was 6.06 ± 0.27 . Adding IB, the curve was further depressed. KCl (60 mmol·L -1) induced contraction on tracheal strips, IB and Sal depressed the contraction with IC 50 values of 4.78 ×10 -6 and 3.18 ×10 -6 mol·L -1 respectively. With combination of IB and Sal, the inhibitory effect was significantly enhanced (P< 0.01 ). CONCLUSION: Either IB or Sal has a significant inhibitory effect on the contraction of tracheal strips induced by KCl, ACh and His. The effect is stronger in a combination with IB and Sal than that each alone.