蛋白激酶C激动剂PMA、阻滞剂H-7及氯胺酮、咪唑安定对兔离体气管平滑肌收缩力的影响

The Effect of PKC-Specific-Activator PMA, Inhibitor H-7, Ketamine and Midazolam on the Contraction of Isolated Rabbit Tracheal Smooth Muscle

目的：探讨蛋白激酶Ｃ（ＰＫＣ）信号传导系统在气管平滑肌张力调节中的作用及氯胺酮、咪唑安定对其的影响。方法：研究不同浓度的ＰＫＣ激动剂ＰＭＡ（３×１０－７～３×１０－５ｍｏｌ／Ｌ）对静息状态下气管平滑肌张力的影响；研究两种浓度的ＰＭＡ（３×１０－６，３×１０－５ｍｏｌ／Ｌ）及特异性ＰＫＣ阻滞剂Ｈ－７（３×１０－５ｍｏｌ／Ｌ）对乙酰胆碱（１０－４ｍｏｌ／Ｌ）诱发气管平滑肌收缩力的调节作用及Ｈ－７、氯胺酮、咪唑安定对ＰＭＡ效应的抑制作用。结果：３×１０－７～３×１０－５ｍｏｌ／Ｌ的ＰＭＡ对静息状态下的气管平滑肌张力无明显影响，３×１０－６ｍｏｌ／Ｌ的ＰＭＡ可明显增强乙酰胆碱诱发张力的峰值和平台值，然而３×１０－５ｍｏｌ／Ｌ的ＰＭＡ并不能进一步增加乙酰胆碱的作用，张力平台值有所下降；３×１０－５ｍｏｌ／Ｌ的Ｈ－７可完全抵消３×１０－６ｍｏｌ／Ｌ的ＰＭＡ效应。１０－３ｍｏｌ／Ｌ氯胺酮和１０－４ｍｏｌ／Ｌ咪唑安定和Ｈ－７有相似的效果。结论：ＰＫＣ信号传导系统的激活并不能单独诱发离体气管平滑肌的收缩，但可使乙酰胆碱的收缩效应增加，氯胺酮和咪唑安定对ＰＫＣ信号传导系统有抑制作用。

Objective:To investigate the role of protein kinase C ( PKC)signal pathway in the regulation of tracheal smooth muscle (TSM) tone and th e effect of ketamine and midazolam on the PKC signal pathway. Methods: By measuring the tones of isolated rabbit TSM, the direct action of different co ncentrations of PKC-specific activator PMA (3×10-7～3×10-5 mol/L) were observed. The effect of two different concentrations of PKC-specific acti vator PMA, inhibitor H-7 and ketamine, midazolam on regulation of contraction in isolated rabbit TSM induced by 10-4 mol/L acetylcholine (ACH) were studie d. Results:3×10-7～3×10-5 mol/L PMA had no effect on the TSM tone; but 3×10-6mol/L PMA could significantly enhanced the contracti on induced by ACH, 3×10-5 mol/L PMA could not further enhance the tension s; 3×10-5 mol/L H-7 could all countervail the effect of 3×10+{-6} mo l/L PMA; 10+{-3} mol/L ketamine and 10-4 mol/L midazolam had the simila r ef fect as H-7. Conclusion:The activation of PKC signal pathway could no t alone induce the contraction of isolated rabbit TSM but could enhance the acti on of ACH; ketamine and midazolam may inhibit the PKC signal pathway.