天母降压散对SHR大鼠的降压作用及其机制

目的:以SHR大鼠为模型,探讨天母降压散的降压作用及其相关降压机制,为临床应用天母降压散治疗高血压病提供实验依据。方法:SHR雄性大鼠60只,适应性喂养1周后,按体质量随机分为6组,分别为模型组,缬沙坦组(12 mg·kg~(-1)),卡托普利组(9 mg·kg~(-1)),氢氯噻嗪组(6.25 mg·kg~(-1)),天母降压散低剂量组(0.36 g·kg~(-1)),天母降压散高剂量组(1.44 mg·kg~(-1)),以WKY大鼠作为正常组,连续灌胃给药16周。采用Softron BP-2010A智能无创血压计测量大鼠尾动脉收缩压(SBP)和心率(HR);采用Adobe Photoshop CS5软件分别对左耳廓、后足固定选取区域对图像进行分析,以评估其对血瘀证的影响;采用Vevo 2100小动物超声影像系统检测大鼠心脏左心室射血分数(LVEF),短轴缩短(FS),左心室收缩末期容积(LVESV),左心室舒张末期容积(LVEDV),左心室收缩末期内径(LVIDs),左心室舒张末期内径(LVIDd),收缩末期室间隔厚度(IVSs),舒张末期室间隔厚度(IVSd);然后处死大鼠并取材(血液,心脏,主动脉,肝脏,肾脏,胫骨),记录心、肝、肾的质量和胫骨长度;苏木素-伊红(HE)染色观察心脏及胸主动脉病理变化;分离血清血浆,采用硝酸还原酶法测定血清一氧化氮(NO)的含量;采用放射免疫法检测血浆3甲氧基肾上腺素(MN),尿素(UREA)及尿酸(UA)的含量;采用免疫组化法检测分析各组胸主动脉一氧化氮合酶(i NOS)和血管内皮生长因子(VEGF)蛋白表达情况。结果:与正常组比较,模型组大鼠SBP及HR升高(P0.05),8周和16周后足r值降低,g值升高(P0.05),LVEF,FS降低,LVESV,LVIDs及IVSd升高(P0.05),心脏质量,心脏质量/胫骨长,肝脏质量,肝脏质量/胫骨长,血浆MN,UREA及UA含量均显著升高,并促进主动脉i NOS,VEGF蛋白的表达(P0.05)。与模型组比较,天母降压散给药组可持续降低SHR大鼠SBP,维持HR稳定(P0.05),升高后足r值,降低后足g值(P0.05),LVEF,FS升高,LVEDV,LVESV,LVIDd,LVIDs降低(P0.05),升高血清NO含量,降低肝脏质量,肝脏质量/胫骨长,血浆MN,UREA,UA含量(P0.05),并下调主动脉i NOS,VEGF蛋白的表达(P0.05)。结论:天母降压散具有一定的降压作用,其作用机制可能主要与保护心功能,改善血管内皮功能,降低儿茶酚胺及镇静镇痛有关。

Antihypertensive Effect of Tianmu Jiangya Powder on SHR Rats and Its Mechanism

Objective: To investigate the antihypertensive effect of Tianmu Jiangya powder and its related antihypertensive mechanism by using SHR rats as a model, and protein expressions provide an experimental basis for the clinical application of Tianmu Jiangya powder in the treatment of hypertension. Method: Sixty male SHR rats were randomly divided into six groups according to body weight after one week of adaptive feeding: model group, valsartan group (12 mg·kg^-1), captopril group (9 mg·kg^-1), hydrochlorothiazide group (6 mg·kg^-1), Tianmu Jiangya powder low and high-dose group (0.36, 1.44 g·kg^-1), WKY rats were used as the normal group, and the intragastric administration lasted for 16 weeks. Softron BP-2010A intelligent non-invasive blood pressure meter was used to measure the systolic blood pressure (SBP)and heart rate (HR) of rat tail arteries. Adobe Photoshop CS5 software was used to analyze the left auricle and claw fixed selected areas to evaluate the effect on blood stasis syndrome. Vevo 2100 small animal ultrasound imaging system detects left ventricular ejection fraction (LVEF), left ventricular shortening (FS), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), left ventricular end-systole dimension (LVIDs), left ventricular end-diastole dimension (LVIDd), interventricular septum end-systolic depth (IVSs), and interventricular septum end-diastolic depth (IVSd). Then the rats were sacrificed and the materials were taken (blood, heart, aorta, liver, kidney, tibia), and the weight of heart, liver, kidney and tibia length were measured and recorded. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of the heart and thoracic aorta. Separation of serum and plasma, and determination of nitric oxide (NO) in serum by nitrate reductase method. Radioimmunoassay was used to detect plasma adrenaline/3 methoxyadrenaline (MN), urea (UREA), and uric acid (UA) contents. The expression of nitric oxide synthase(iNOS) and vascular endothelial growth factor(VEGF) protein in thoracic aorta of each group was detected and analyzed by immunohistochemical method. Result: Compared with normal group, the SBP and HR of the rats in model group were significantly increased (P<0.05). The r value of the claw was significantly reduced and the g value was significantly increased at 8 and 16 weeks (P<0.05). LVEF and FS significantly decreased, LVESV, LVIDs, IVSd increased significantly (P<0.05). Heart weight, heart weight /tibia length, liver weight and liver weight /tibia length, plasma of MN, UREA, and UA contents significantly increased, and promoted the expression of iNOS and VEGF proteins in the aortic (P<0.05). Compared with the model group, the Tianmu Jiangya powder administration group could continuously reduce SBP in SHR rats, maintain HR stability (P<0.05),significantly increase the claw of r value, lower the claw of g value(P<0.05). LVEF, FS significantly increased, LVEDV, LVESV, LVIDd and LVIDs significantly decreased (P<0.05), significantly increased serum NO content, decreased liver weight, liver weight/tibia length, plasma MN, UREA, UA content (P<0.05), and down-regulated the expression of iNOS and VEGF protein in the aorta(P<0.05). Conclusion: Tianmu Jiangya powder has a certain antihypertensive effect, and its mechanism may be mainly related to protecting heart function, improving vascular endothelial function, reducing catecholamines and sedative analgesia.