内皮素1和BQ-123对自发性高血压大鼠动脉平滑肌细胞腺苷三磷酸酶活性及mRNA表达的影响

Effect of Endothein-1 and BQ-123 on Adenosine Triphosphatase Activity and mRNA Expression in Aortic Smooth Muscle Cells from Spontanously Hypertensive Rats

目的观察内皮素1及其受体拮抗剂BQ-123对自发性高血压大鼠及Wistar-Kyoto(WKY)大鼠动脉平滑肌细胞膜腺苷三磷酸酶(ATPase)活性及其mRNA表达的影响。方法组织块种植法培养自发性高血压和WKY大鼠胸主动脉平滑肌细胞。以WKY大鼠为对照,采用生化酶学方法和逆转录聚合酶链反应,观察不同浓度的内皮素1(10-7、10-8、10-9mol/L)及其受体拮抗剂BQ-123(10-6、10-7、10-8mol/L)对自发性高血压大鼠动脉平滑肌细胞膜Na+,K+-ATPase、Ca2+-ATPase活性及mRNA表达的影响。结果内皮素1能减弱自发性高血压大鼠动脉平滑肌细胞两种ATPase活性(P<0.01)及膜钙ATP酶亚型1(PMCA1)表达(P<0.01)。BQ-123能部分逆转内皮素1所致两种ATPase活性减弱(P<0.01)及PMCA1表达下调(P<0.01),而内皮素1对Na+,K+-ATPaseα1-亚单位mRNA表达水平无明显改变(P>0.05)。结论内皮素1抑制Na+,K+-ATPase、Ca2+-ATPase活性,可能是通过ETA受体途径介导,且其对Ca2+-ATPase活性的影响可能发挥在转录水平。BQ-123通过阻断ETA受体逆转内皮素1对自发性高血压大鼠Na+,K+-ATPase、Ca2+-ATPase活性的影响。

Aim To study the effects of endothelin-1（ET-1） and BQ-123 on activity and mRNA expression of adenosine triphosphatase（ATPase） in Aortic Smooth muscle cells（ASMC） from spontaneously hypertensive rats（SHR）and Wistar-Kyoto（WKY） rat. Methods The ASMC were isolated from SHR and WKY rats.ATPase activity in cultured ASMCs were determined by spectrophotography and mRNA level of Na＋,K＋-ATPase α1-subunit,PMCA1 were measured by semiquantitative reverse transcription polymerase chain reaction（RT-PCR）. Results ET-1 significantly attenuated activity of two kinds of ATPase（P0.01）and PMCA1 mRNA expression（P0.01） in ASMC from SHR.BQ-123 increased two kinds of ATPase activity（P0.01） and upregulated expression of PMCA1 mRNA（P0.01）,which treated by ET-1.The level of Na＋,K＋-ATPase α1-subunit mRNA expression had no alteration after intervened by ET-1（P0.05）. Conclusion ET-1 suppressed Na＋,K＋-ATPase,Ca2＋-ATPase activity,which may be mediated by ETA receptor.The influence of ET-1 Ca2＋-ATPase activity may play in the transcriptional level.BQ-123 reversed the effect of ET-1 on the activities of SHR ASMCs Na＋,K＋-ATPase and Ca2＋-ATPase by blocking the ETA receptor.