依那普利和氯沙坦对自发性高血压大鼠同型半胱氨酸及一氧化氮水平的影响

Effects of Enalapril and Losartan on Plasma Homocysteine and Nitric Oxide Levels in Spontaneously Hypertensive Rats

目的 :探讨血浆同型半胱氨酸 (Hcy)、叶酸、维生素 (Vit)B12 和一氧化氮 (NO)水平与高血压的关系 ,以及依那普利、氯沙坦在降压的同时对Hcy、叶酸、VitB12 和NO水平的影响。 方法 :雄性自发性高血压大鼠 (SHR)分为 3组 (n =6 ) :依那普利组 1 5mg/(kg·d)灌胃 ,氯沙坦组 37 5mg/(kg·d)灌胃 ,SHR对照组及Wistar kyoto(WKY)对照组用等量蒸馏水灌胃。采用全自动荧光偏振免疫分析法测定血浆Hcy水平 ,离子捕捉分析法测定血浆叶酸水平 ,微粒子酶固有因子分析法测定血浆VitB12 水平 ;Griess法测定血浆NO代谢产物硝酸盐 (NO-3 )水平。 结果 :①SHR对照组血浆Hcy、叶酸水平与WKY对照组相比无显著性差异 (P >0 0 5) ;②SHR对照组血浆VitB12水平较WKY对照组明显升高 ;③依那普利、氯沙坦治疗后对Hcy、叶酸及VitB12 水平均无明显影响 ;④SHR对照组血浆NO-3 水平明显下降 ;⑤依那普利治疗 2周后NO-3 含量回升至 4 1 2 6± 5 1 6 μmol/L ,与SHR对照组之间有显著性差异 (P <0 0 1 ) ;氯沙坦治疗 2周后NO-3 含量虽有上升 ( 35 0 3± 4 31 μmol/L) ,但与未治疗的SHR相比无显著性差异 (P>0 0 5)。 结论 :本研究未发现Hcy水平与高血压有相关性 ;SHR较高的VitB12 水平可能与预防Hcy的危险性有关 ,但也不排?

Objective:To probe into the relationship of hypertension to plasma homocysteine(Hcy),folate,vitamin(Vit)B 12 levels,nitric oxide(NO)concentration,and to investigate the effects of enalapril and losartan on Hcy,folate,VitB 12 and NO. Methods:Eighteen 14 week old male spontaneously hypertensive rats(SHR)were divided into three groups(n=6,each).Enalapril[15*!mg/(kg·d)],losartan[37 5*!mg/(kg·d)]and equal volume of distilled water were administered respectively for 2 weeks by gavage.Fluorescence polarization immunoassay was used to measure plasma homocysteine level,an ion capture assay was used for the quantitative determination of folate,and microparticle enzyme intrinsic factor assay was used for the quantitative determination of VitB 12 .Plasma nitrate(NO - 3),metabolic production of NO,was measured by griess reaction. Results:There were no differences in the levels of plasma Hcy and folate between subgroups of SHR and WKY,but Vit B 12 level was significantly increased in SHR.Enalapril and losartan had no effects on Hcy,folate and elevated VitB 12 levels.NO - 3 concentration was significantly decreased in SHR.NO - 3 concentration returned to normal after enalapril treatment.NO - 3 concentration was increased after losartan treatment,but still under the normal level. Conclusion:The results show that there is no relationship between Hcy and hypertension.The increased VitB 12 level may be related to the prevention of hyperhomocysteinemia.The reduced NO - 3 level is significantly correlated with hypertension enalapril is superior to losartan in raising NO - 3 level and improving endothelium function.