感觉神经损伤性盐敏感性高血压大鼠心、肾AT1R的表达

AT1R Expression in the Heart and Kidney of Rats with Salt-Sensitive Hypertension Induced by Sensory Denervation

目的对感觉神经损伤性盐敏感性高血压大鼠的心肌、肾脏组织中的血管紧张素Ⅱ1型受体(AT1R)在mRNA和受体水平的表达进行检测,探讨AT1R与盐敏感性高血压的关系。方法用乳鼠皮下注射辣椒辣素法建立模型。哺乳期后,大鼠被随机分成4组:对照+正常盐饮食组(CON-NS);对照+高盐饮食组(CON-HS);辣椒辣素+正常盐饮食组(CAP-NS);辣椒辣素+高盐饮食组(CAP-HS)。至7周龄(分组饲养后第4周)处死大鼠,免疫组织化学方法和反转录-聚合酶链式反应(RT-PCR)分别检测大鼠心肌和肾脏AT1R蛋白,以及AT1 R mRNA的表达。结果①Wistar大鼠在给予不同程度的感觉神经损伤和饲料干预后,各组大鼠尾部收缩压均有明显增加,最终CAP-HS组的尾收缩压显著高于其他三组(P<0.01)。②免疫组织化学结果显示,CAP-HS组组织有显著的AT1R蛋白表达(P<0.01);CON-HS组肾脏、心肌组织中AT1R蛋白表达高于CON-NS组(P<0.05)。③RT-PCR检测基因表达,与对照组CON-NS相比,实验组CAP-HS的AT1R mRNA表达显著升高(P<0.01);CON-HS组肾脏、心肌组织中AT1 R mRNA表达有显著性(P<0.05)。结论感觉神经损伤性盐敏感性高血压大鼠心、肾AT1R表达升高,AT1R表达水平的差异可能与盐敏感性高血压的形成有关。

Objective To investigate the expression of AT1R in heart and kidney of rats with salt-sensitive hypertension induced by sensory denervation,and to explore their role in the development of salt-sensitive hypertension.Methods Newborn male Wistar rats were given capsaicin subcutaneously to establish the model.After the weaning period,the rats were divided into 4 groups and fed with different salt diets for 4 weeks： control plus normal salt diet（CON-NS）,control plus high salt diet（CON-HS）,capsaicin pretreatment plus normal salt diet（CAP-NS）,and capsaicin plus high salt diet（CAP-HS）.The rats were killed at 4 weeks after treatment.Immunohistochemistry was used to detect the expression of AT1R protein in the heart and kidney tissues.The expression of AT1R mRNA in heart and kidney was determined by reverse transcription polymerase chain reaction.Results ①The tail-cuff systolic blood pressure was significantly higher in the CAP-HS rats than that in the other three groups at the age of 7 weeks（P0.01）.②Immunohistochemistry results showed a significantly higher AT1R protein expression in the CAP-HS group than in the CON-NS group（P0.01）,and the AT1R protein expression in the kidney and heart tissue was significantly higher in the CON-HS group than in the CON-NS group（P0.05）.③RT-PCR results showed that AT1R mRNA expression of the experimental groups CAP-HS and CON-HS was significantly higher than that in the CON-NS group（P0.01,and P0.05,respectively）.Conclusions The over-expression of AT1R protein and AT1R mRNA in the heart and kidney may be associated with the increase of blood pressure in the rats with salt-sensitive hypertension.