转换酶抑制剂及AT_1受体拮抗剂对血管紧张素Ⅱ(AngⅡ)受体的作用

Evaluation of insulin sensitivity, using oral glucose tolerance test and insulin release test in essential hypertensive patient

目的：本文探讨转换酶抑制剂及ＡＴ_１受体拮抗剂对血管紧张素 Ⅱ（ＡｎｇⅡ）受体的作用方法：ＳＨＲ与ＷＫＹ大鼠服用两种不同药物（ｂｅｎａｘｅｐｒｉｌ和ｌｏｓａｒｔａｎ），检测动物肾皮质ＡＴ_１ｍＲＮＡ表达情况和ＡＴ_１受体密度。原发性高血压患者服用ｂｅｎａｘｅｐｒｉｌ或ｌｏｓａｒｔａｎ后检测血小板ＡＴ_１ｍＲＮＡ的表达情况。结果：ＳＨＲ喂用ｂｅｎａｚｅｐｒｉｌ后肾脏ＡＴ_１ｍＲＮＡ和ＡＴ_１受体密度均无明显变化，而喂用ｌｏｓａｒｔａｎ后肾脏ＡＴ_１ｍＲＮＡ及ＡＴ_１受体密度则明显降低。ＳＨＲ肾ＡＴ_１受体密度在ｂｅｎａｚｅｐｒｉｌ组无明显变化，而在ｌｏｓａｒｔａｎ组明显降低。相应的高血压患者服用 ｂｅｎａｘｅｅｒｉｌ后血小板 ＡＴ_１ ｍＲＮＡ无明显变化，而 ｌｏｓａｒｔａｎ组ｂｅｎａｘｅｐｒｉｌ后血小板ＡＴ_１ｍＲＮＡ的表达明显降低。结论：ＡＴ_１ＲＡ能下调ＡｎｇⅡ受体密度而 ＡＣＥＩ则无此作用，ＡＣＥＩ和ＡＴ_１ＲＡ对肾皮质ＲＡＳ系统作用机制是不同的。测定人血小板的ＡＴ_１ｍＲＮＡ是反映ＡＴ_１受体状况的有用指标。

Objective: To survey the effect of angiotensin converting enzyme inhibitor(ACEI) and AT_1 receptor antagonists (AT_1RA) AT_1 receptor mRHA expression. Methods:ACEI and AT_1RA were given SHR and Wistar- Kyoto rats (WKY) for 3 - 4 weeks. Renal cortex AT_1 receptor mRNA in SHR and WKY were measured with reverse transcription polymerase chain reaction (n = 6, n = 6 respectively). Renal cortex angiotensin Ⅱ receptor density of SHR and WKY were measured with ^(125)I-Ang Ⅱ binding method. Also, 12 cases hypertension patients were recieved these two kinds drugs, platelet AT_1 receptor mRNA were analysed. Results: (1)Renal cortex AT_1 receptor mRNA and Ang Ⅱ receptor density in SHR were significantly lower in SHR treated with Losartan, but no changes in control WKY group. No significant changes in both groups treated with ACEI (enalapril ); (2 ) Platelet AT_1 receptor mRNA was significant lower in EH patients treated with losartan but not with ACEI and benazepril. Conclusion: Renin-Angiotensin system (RAS ) seems to be blocked by ACEI and AT_1R in different mechanism. Downregulation of AT_1 receptor only in AT_1R group but not in ACEI group and the determination of platelet AT_1 receptor mRNA in patients may be a useful index of activity of AT_1 receptor.