依那普利对自发性高血压大鼠平滑肌细胞Gqα基因表达的影响

The Effect of Enalapril on Gqα Gene Expression in Smooth Muscle Cells of SHR

（１）自发性高血压大鼠是否存在 Ｇｑα基因表达的异常；（２）ＡＣＥＩ抑制血管平滑肌的增殖是否与抑制Ｇｑα基因表达有关。方法：采用半定量ＲＴ－ＰＣＲ方法，观察ＳＨＲ及ＷＫＹ主动脉血管平滑肌细胞静止期及增殖期Ｇｑα基因表达情况以及依那普利对Ｇｑα基因表达的影响。结果：（１）静止期， ＳＨＲ及 ＷＫＹ血管平滑肌细胞 Ｇｑα ｍＲＮＡ表达无明显差别；在１０％小牛血清刺激下，ＳＨＲ血管平滑肌细胞Ｇｑα ｍＲＮＡ表达增加四倍（Ｐ＜０．０１）；（２）依那普利对静止期ＳＨＲＧｑαｍＲＮＡ表达无明显作用，对小牛血清引起的Ｇｑα ｍＲＮＡ表达的增加有明显抑制作用，且呈浓度及时间依赖性；（３）非特异性肽类 ＡｎｇⅡ受体阻制剂无此作用。结论：ＳＨＲ的Ｇｑα基因表达反应性增加，依那普利对高血压病的治疗除抑制ＡＣＥ外，通过对Ｇｑ蛋白基因表达的抑制也起一定的作用。

Objective: Gqα is an important G protein that mediates prolif eration and calcium influx of vascular smooth muscle cells (VSMCs ). This study investigated: (1) Whether there is abnormal on Gqαgene expression in VSMC in SHR; (2 )Whether ACEI inhibited VSMCs proliferation is mediated inhibiting Gqαgene expression. Methods: RT-PCR was used to investigate the difference in the levels of GqαmRNA between quiescent and proliferous VSMCs in SHR (15 weeks) and the effect of Enalapril,stand- ing for ACEI,on mRNA level. Result: (1) In quiescent VSMCs, no significant differences were seen in the level of GqαmRNA between SHR and WKY. 10% calf serum stimulation showed a 4-fold increase in level of Gqα mRNA as compared to the quiescent VSMCs from SHR (P< 0.01) 4 (2)Enalapril has been shown no effect on the level of Gqα mRNA in the quiescent VSMCs ,but significantly inhibited the increased Gqα mRNA level induced by calf serum (P<0. 01 ),and in time and dose-dependent manner; (3)Non- specific Ang Ⅱ receptor peptide inhibitor had no effect on it. Conclusion: The response of Gqα gene expression was highly increased in SHR; Enalapril could have therapy effect on hy- pertension through inhibiting Gqαgene expression, besides in- hibiting ACE.