高血压大鼠主动脉平滑肌细胞Cl~-通道的改变

目的　探讨在高血压状态下 ,大鼠主动脉平滑肌细胞Cl-通道的改变。方法　采用两肾两夹 (2kidney 2clip ,2K2C)肾血管性高血压大鼠 (renovascularhypertensiverats,RVHR)模型 ,在术后 1wk～ 12wk ,取大鼠胸主动脉平滑肌 ,做主动脉环张力实验 ,观察Cl-通道阻断剂DIDS(4,4 di isothiocyanato stilbene 2 ,2’disulphonate)和NPPB5 nitro 2 (3 phenylpropy lamino)benzonicacid]对苯肾上腺素引起的主动脉平滑肌 (aorticvascularsmoothmuscle,AVSM )收缩反应的影响。结果　在术后 1wk和 4wk ,30 0 μmol·L-1DIDS和 10 0 μmol·L-1NPPB对苯肾上腺素引起的高血压手术组大鼠主动脉平滑肌收缩反应的抑制作用与假手术组相比差异无显著性 ;在术后 8wk和 12wk ,30 0 μmol·L-1DIDS和10 0 μmol·L-1NPPB对苯肾上腺素引起的高血压手术组大鼠主动脉平滑肌收缩反应的抑制作用低于假手术组 ;随术后时间的延长 ,血压的升高 ,DIDS和NPPB对主动脉平滑肌收缩反应的抑制作用逐渐降低。结论　在高血压状态下 ,大鼠主动脉平滑肌细胞DIDS和NPPB敏感的Cl-通道的活性发生了改变 ,DIDS和NPPB敏感的Cl-通道与高血压病的发生和发展密切相关。

Change of Cl- channels in aortic smooth muscle cells of hypertensive rats

Aim To investigate change in Cl- channels of hypertensive rats aortic smooth muscle cells. Methods 2 kidney-2 clip renovascular hypertensive rats(RVHR) model was established. In thoracic aorta smooth muscles from the hypertensive rats 1～12 weeks after operation,the changes of tension of aortic rings were recorded in vitro. Effects of Cl- channel blookers,DIDS(4,4-diisothiocyanato-stilbene-2,2'disulphonate)and NPPB5-nitro-2-(3-phenylpropy-lamino) benzonic acid], in different concentration on contractile response of hypertensive rats aorta smooth muscle induced by 10 μmol·L -1 phenylephrine were observed.Results The difference of inhibitory effects of 300 μmol·L -1 DIDS and 100 μmol·L -1 NPPB on Phe-induced contractile response between RVHR and sham-operated rats was not evident.Inhibitory effects of 300 μmol·L -1 DIDS and 100 μmol·L -1 NPPB on contractile response of hypertensive rats aorta smooth muscle induced by 10 μmol·L -1 phenylephrine were lower than those of sham-operated rats in 8 weeks and 12 weeks after operation. With extension of time after operation and gradual increase of blood pressure in RVHR,inhibitory effects of DIDS and NPPB on Phe-induced contractile response gradually reduced.Conclusion Action of DIDS-sensitive and NPPB-sensitive Cl- channels in hypertensive rats aortic vascular smooth muscle cells changes. DIDS-sensitive and NPPB-sensitive Cl- channels play an important role in development and maintenance of hypertension.