【摘要】 目的　观察近年新发现的活性肽尾加压素 (UrotensinⅡ ,UⅡ )在大鼠气道平滑肌细胞增殖中的作用及其机制。方法　 (1)采用3H 胸腺嘧啶 (3H TdR)掺入法测定UⅡ对原代培养的大鼠气道平滑肌细胞 (ASMC)DNA合成的影响 ,应用不同阻断剂观察UⅡ诱导细胞DNA合成的信号转导通路。(2 )采用Fura 2 /AM荧光探针 ,测定UⅡ对胞浆游离钙浓度的影响。结果　 (1)UⅡ呈浓度 (10 -10 ～10 -6mol/L)依赖性刺激ASMC3H TdR掺入 ,10 -6mol/L时 ,为对照组的 7倍 (P <0 0 1) ;(2 )蛋白激酶C(PKC)阻断剂H7、丝裂素活化蛋白激酶 (MAPK)阻断剂PD980 59及钙通道阻断剂尼卡的平均能抑制UⅡ刺激的ASMC3H TdR掺入 ,其抑制率分别为 2 9% (P <0 0 5 ) ,45 % (P <0 0 1)及 2 8% (P <0 0 5 ) ,而钙调素依赖性蛋白激酶 (CaM PK)阻断剂W7无影响 (P >0 0 5 ) ;(3)钙调神经磷酸酶 (CaN)阻断剂环孢霉素10 -8～ 10 -6mol/L呈浓度依赖性抑制UⅡ刺激的ASMC3H TdR掺入 ,10 -6mol/L时抑制率为 76 % (P <0 0 1)。 (4 )UⅡ 10 -6mol/L刺激胞浆游离钙浓度缓慢升高 18% (P <0 0 1)。结论　UⅡ刺激ASMCDNA合成 ,其机制与外钙内流、胞浆Ca2 +增加、PKC、MAPK及CaN信号转导通路介导有关。更多还原

【Abstract】 Objective To investigate the effect and mechanism of Urotensin Ⅱ on the airway smooth muscle cell proliferation. Methods (1) Using 3H-TdR incorporation to determine the effect of Urotensin Ⅱ on the rat airway smooth muscle cells DNA synthesis. Different inhibitors were used to study the role of different signal transduction pathway such as protein kinase C(PKC), mitogen-activated protein kinase (MAPK), Calcineurin (CaN), Calmodulin-dependent protein kinase (CaM-PK) and calcium channel in the mitogenic effect of Urotensin Ⅱ on the airway smooth muscle cells. (2) Using Fura-2/AM to measure the effect of Urotensin Ⅱ on the cytosolic free calcium concentration. Results (1) Urotensin Ⅱ (10 -10 ～10 -6 mol/L) increased the airway smooth muscle cell 3H-TdR incorporation in a dose-dependent manner and Urotensin Ⅱ 10 -6 mol/L reached the maximal effect. It was seven times as high as that of control ( P <0 01). (2) H 7, PD 98059 , and nicardipine, inhibitors of PKC, MAPK and calcium channel, significantly inhibited Urotensin Ⅱ (10 -7 mol/L)-stimulated airway smooth muscle cell 3H-TdR incorporation, with the inhibitory rate of 29% ( P <0.05), 45%( P <0 01), and 28% respectively ( P <0.05). W 7, an inhibitor of CaM-PK, had no effect ( P >0.05). (3) Cyclosporin A (10 -8 ～10 -6 mol/L), inhibitor of CaN, an inhibited the airway smooth muscle cell 3H-TdR incorporation induced by Urotensin Ⅱ(10 -7 mol/L) in a dose-dependent manner, with the inhibitory rate of 76% at 10 -6 mol/L ( P <0 01). (4) Urotensin Ⅱ(10 -6 mol/L) promoted cytosolic free calcium concentration increase by 18% ( P <0 01). Conclusion The effect of Urotensin Ⅱ-stimulated airway smooth muscle cells DNA synthesis is mediated by Ca 2+ , PKC, MAPK and CaN signal transduction pathway.更多还原