自发性高血压大鼠肾脏血管紧张素转换酶2的表达

Expressions of angiotensin converting enzyme 2 mRNA and protein in the kidneys in spontaneously hypertensive rats

目的观察不同月龄的自发性高血压大鼠(SHR)的肾脏血管紧张素转换酶2(ACE2)的mRNA和蛋白质表达水平,探讨ACE2与血压状态的内在联系。方法12周龄雄性自发性高血压大鼠(SHR)18只和12周龄Wistar-Kyo-to(WKY)大鼠18只。随机分为SHR组和WKY组,每组抽取各9只处死后与喂养12周后处死的24周龄大鼠一并进行ACE2的检测。采用实时定量RT-PCR法检测ACE2 mRNA的表达,免疫组织化学检测ACE2蛋白的表达。结果与同周龄WKY组比较,SHR组大鼠的血压显著增加(P均<0.001),ACE2 mRNA表达显著降低(P均<0.001);与12周龄SHR组比较,24周龄SHR的血压显著增加(P<0.01),ACE2 mRNA表达显著降低(P<0.01);与同周龄的WKY组比较,SHR组肾脏ACE2免疫染色表达显著减少。结论肾脏ACE2 mRNA和蛋白质的表达与血压升高相关。

Objective To investigate the relationship of ACE2 and blood pressure on expression levels of mRNA and protein in spontaneously hypertensive rats（SHR）. Methods 18 male （ 12 weeks old） SHRs and 18 male （ 12 weeks old） Wistar Kyoto （WKY） rats were randomly divided into two groups： the WKY-control group（ n = 18） and the SHR group（ n = 18）. Nine SHRs and nine WKY rats were randomly drawn for detection. After 12 weeks feeding, other rats were executed for detection. The mRNA expression of ACE2 was determined by real-time quantitative RT-PCR and the protein level of ACE2 by immunohistochemistry. Resuits （1） SBP in the 12- and 24- weeks old SHR groups was increased compared with that in the WKY greup （all P 〈 0.001）. SBP in the 24-weeks old SHR group was increased compared with that in the 12- week old SHR group （ P 〈 0.01）. （2） Expression of ACE2 mRNA in the 12- and 24- weeks old SHR groups was significandy lower than that in the WKY group （all P 〈 0.001 ） and in the 24- weeks old SHR group was significantly lower than that in the 12-weeks old SHR group （ P 〈 0.01）. （3） Immunohistochemistry showed that positive reaction of ACE2 protein was all stained brown and found in the kidneys. ACE2 had a uniform distribution of thick brown granules in the WKY group and a comparatively rare distribution by brown granules in the SHR group. Conclusion There are correlations between the renal expressions of mRNA and protein ACE2 and blood pressure.