C神经兴奋体外引起豚鼠气管和支气管收缩的介质差异(英文)

Mediator difference in contractions between trachea and bronchus of guinea pig induced by stimulation of C-fibers in vitro

氯苯那敏和色甘酸钠(Cro)能降低豚鼠气管C神经兴奋引起的平滑肌收缩反应;渐增浓度的P物质(0.1—3.0μmol·L^(-1))引起的气管片收缩效应也可被Cro处理降低;然而支气管条的收缩反应却不受上述药物影响,但能被阿托品处理降低。提示C神经末梢兴奋平滑肌收缩的介质在豚鼠的气管和支气管部位有明显差异。

In trachea and bronchus of guinea pig in vitro, electric field stimulation (EFS) induced a rapid contraction (phase I) followed by a long-lasting contraction (phase Ⅱ). The pretreatments of chlorphenamine (Chl) 1 μ mol·L-1 and disodium cromoglicate (Cro) 10 μmol·L-1 reduced the tracheal contraction of phase Ⅱ from 49 ±23 mg and 34 ± 18 mg to 27±21 and 18±12 mg, respectively. The contractile responses of the tracheae to increasing concentrations of substance P (SP) 0. 1 - 3. 0 μmol·L-1 were reduced by the pretreatment of Cro 10 μmol· L-1 (P<0. 01). On the contrary, the contractile responses of the bronchi were not inhibited by Cro or Chl but were inhibited by pretreatment of atropine 1 μmol·L-1 from 61 ±36 mg to 36±15 mg. These results show that there are different mechanisms in the EFS-induced contractions between the trachea and bronchus; that different mediators amplify the phase Ⅱ contractions.