人类心房利钠肽基因在自发性高血压大鼠体内表达及其对血压、心脏、血管的影响

Expressionof human atrial natriuretic peptide gene and the effective for the blood pressure,heart and the blood vessel in the spontaneously hypertensive rats

目的研究人类心房利钠肽(hANP)基因在自发性高血压大鼠(SHR)体内表达、持续时间和对血压及心脏、血管的影响。方法 12只8周龄雄性SHR,随机分为两组,于左腿股四头肌注射pcDNA3.1-hANP质粒的为实验组,在同一部位注射pcDNA3.1空质粒的为对照组,每周测量大鼠尾动脉收缩压,及利用放射免疫方法监测血中hANP水平;10周后处死动物,RT-PCR和Western印迹杂交技术检测hANP基因表达情况;分别称量体重、全心脏和左心室重量,大体评价对心肌重构的影响;苏木素-伊红(HE)染色和胶原组织学(VG)染色观察对心脏、血管组织形态学的影响。结果转基因后第1周起与对照组比较,实验组血压开始下降,两组动物一直相差(12±3.1)mmHg(P<0.05),其作用可持续10周;且放射免疫方法监测实验组血中hANP水平较高;RT-PCR和Western印迹杂交技术检测显示实验组hANP基因在肌肉组织中高效表达,对照组则未见表达;实验组心脏重量/体重比和左心室重量/心脏重量比明显低于对照组。组织形态学分析结果显示实验组心肌、血管组织细胞形态基本正常,胶原沉积明显减少。结论肌肉注射法将hANP基因导入SHR,hANP基因可在肌肉组织中高效表达,且hANP可释放如血,降低SHR的血压并对心脏、血管高血压靶器官的损害起到了预防作用。显示了hANP基因对高血压患者治疗的可能性。

Objective： To investigation the expression, the long term and the effective of the heart and the blood vessel in the spontaneously hypertensive rats （SHR） after the human atrial natriuretic peptide （hANP） gene delivery. Methods： Twelve eight- week - old male SHR were divided into two groups randomly. The skeletal muscle of the SHR in infected group （ n = 6） were injection of pcDNA3. 1 -CMV -hANP plasmid. Control group （n = 6） were injection of pcDNA3.1 -CMV plasmid into the same locus. After the gene delivery, the systolic pressure and the level of hANP in the plasm of the SHR were both measured every week by measuring the caudal artery and utilization of radio - immunity technique. After ten weeks the Animals were put to death, the station of the ex- pression of hANP gene were measured by utilizating RT - PCR and Western blot ; Body weight, heart weight and left ventricle weight were measured to evaluate the effective of reconstitution of the myocardium rougly ; the effective of pathomorphology of the heart and the blood vessel, were evaluated by Hematoxylin -Eosin （HE） and Van Gieson （VG）. Results： From the first week after the injection of pcDNA3.1 - CMV - hANP plasmid into SHR, the blood pressure of the infected group began to reduce compared with the control group. A significant blood pressure difference （ up to 12.0 ＋ 2. 55mmHg, P 〈 0. 05 ） continued for 10 weeks. The high level of hANP in the infected group was detected by the Method of radio - immunity. The result of reverse ranscription - polymerase chain reaction （RT- PCR） and Western blot showed that hANP gene can be expressed efficiently in the muscles, but the control group had no expre- sstion. The result of HW/BW and VLW/HW showed that the ratio of the infected group was decreased markedly. Morphologial analy- sis shows that cardiac hypertrophy injury were also attenuated in the infected group. Conclusion： hANP gene were delivered into SHR through muscle injections, it can be expressed efficiently in the muscles and its expresstion protein can be released into blood circula- tion in SHR. it can not only stably deduce blood pressure, but also prevent the injury of target organic as asresuh of hypertension, such as reconstitution in cardiovascular system. That result suggests the feasibility of hANP gene therapy in human hypertension.