四氢生物蝶呤通过增加磷酸化蛋白激酶B的表达改善高血压小鼠左心室舒张功能  

Tetrahydrobiopterin improves left ventricular diastolic function possibly through upregulating phosphorylated protein kinase B expression in hypertensive mice induced by deoxycorticosterone acetate

作　　者：王琼英[1] 杨米娜[2] 许涵[1] 赵洋[1] 林欣[1] 张小卫[1] 赵锋[1] 赵旭[1] 寇晓庆 白锋[1] 余静[1] 

机构地区：[1]兰州大学第二医院高血压科,730030 [2]延安大学咸阳医院心血管一科

出　　处：《中华心血管病杂志》2016年第9期759-765,共7页Chinese Journal of Cardiology

基　　金：国家自然科学基金（81270332）;甘肃省自然基金项目（1104FKCA150,1606RJZA088）

摘　　要：目的 探讨四氢生物蝶呤（BH4）改善高血压小鼠左心室舒张功能的作用与磷脂酰肌醇3激酶（PI3K）/蛋白激酶B（Akt）信号通路及Akt磷酸化水平的关系.方法 采用10周龄雄性C57BL/6小鼠建立DOCA-盐型高血压小鼠模型,同周龄假手术小鼠作为对照.将小鼠分为4组,分别为假手术组（n=20）、假手术＋ BH4组（n=20）、DOCA组（n=22）和DOCA ＋BH4组（n=22）,各组行相应的手术后14 d,予以假手术＋BH4组和DOCA ＋BH4组小鼠2.5％的BH4溶液0.1 ml/10 g灌胃,同时予以假手术组和DOCA组小鼠等体积生理盐水灌胃.干预7d后,测定鼠尾动脉压;彩色多普勒超声心动图和导管法血液动力学评价小鼠心脏结构与功能;高效液相色谱法检测小鼠左心室心肌组织BH4和二氢生物蝶呤（BH2）含量;免疫组织化学法检测磷酸化受磷蛋白（p-PLB）的表达;ELISA法检测小鼠左心室心肌组织中环磷鸟嘌呤核苷（cGMP）、丙二醛（MDA）、一氧化氮（NO）含量和超氧化物歧化酶（SOD）活性;Western blot检测小鼠左心室心肌组织中PI3K、Akt和磷酸化（p）-Akt的表达.结果 （1）各组小鼠收缩压和舒张压：DOCA组小鼠收缩压和舒张压均明显高于假手术组（P均＜0.05）.DOCA＋BH4组小鼠收缩压明显低于DOCA组（P=0.027）,舒张压两组间差异无统计学意义.（2）各组小鼠左心室功能：DOCA组小鼠左心室舒张功能指标二尖瓣环舒张早期组织运动速度（E＇）、E＇/二尖瓣环舒张晚期组织运动速度（A＇）均明显低于假手术组,二尖瓣口舒张早期血流峰值速度（E）/E＇明显高于假手术组（P均＜0.05）,DOCA＋ BH4组E ＇明显高于DOCA组,E/E＇明显低于DOCA组（P均＜0.05）.DOCA组小鼠左心室舒张末压（LVEDP）、左心室舒张末压力容积系数（EDPVR）和左心室松弛时间常数Tau指数均明显高于假手术组（P分别为0.002、0.011和0.016）.DOCA ＋BH4组小鼠EDPVR和Tau指数则明显低于DOCObjective To investigate whether tetrahydrobiopterin （BH4） could improve left ventricular diastolic function through phosphoinositide-3 kinase/protein kinase B （PI3K/Akt） signaling pathway in hypertensive mice.Methods Ten-week-old male C57BL/6 mice were used to establish the deoxycorticosterone acetate （DOCA）-salt hypertensive model,age matched Sham mice serve as the controls.Mice were divided into four groups：Sham （n =20）,Sham ＋ BH4 （n =20）,DOCA （n =22）,and DOCA ＋ BH4 （n =22）.On the t4 days after surgery,mice in Sham ＋ BH4 and DOCA ＋ BH4 groups received BH4 （0.1 ml/10 g） supplement for 7 days,while mice in Sham and DOCA groups were given equal volume of normal saline.The blood pressure measurements were performed 7 days later.Hemodynamic and echocardiographic parameters were used to assess left ventricular functions.High performance liquid chromatography （HPLC） analysis was used to measure cardiac biopterins BH4 and BH2.The phosphorylated phospholamban （p-PLB） was detected by immunohistochemical staining.PI3 K,Akt and phosphorylated Akt were assayed with Western blot analysis.Results （1） The systolic and diastolic blood pressure of DOCA group were significantly higher than control group （P ＜ 0.05）.Compared with DOCA group,the systolic blood pressure was lower in DOCA ＋ BH4 mice （P =0.027）.Diastolic blood pressure was similar between the groups.（2） Compared with Sham group,the left ventricular diastolic function indexes such as mitral annulus velocity （E＇） and E＇/A＇ratio were significantly lower,while the E/E＇ratio was significantly higher （P ＜ 0.05） in DOCA mice.The E/E＇ratio of DOCA ＋ BH4 group was significantly lower than that of DOCA group （P ＜ 0.05）.Compared with Sham group,the lefi ventricular end-diastolic pressure （LVEDP）,left ventricular end-diastolic pressure volumetric coefficient （EDPVR） and lefi ventricular relaxation time constant Tau index were significantly higher in DOCA mice （P =0.002,0.01

关 键 词：高血压 生物蝶呤 

分 类 号：R544.1[医药卫生—心血管疾病]