Anti-hypertensive effect of water extract of danshen on renovascular hypertension through inhibition of the renin angiotensin system

A study was designed to elucidate the mechanism of anti-hypertensive effects of danshen in the two-kidney, one clip (2K1C) Goldblatt renovascular hypertensive model, which is the renin-angiotensin system (RAS)-dependent hypertensive model. We investigated the effects of water extracts of danshen on the angiotensin converting enzyme (ACE) activities, systolic blood pressure (SBP), and hormone levels in the plasma of 2K1C rats. ACE activity was inhibited by the addition of danshen extract in a dose-dependent manner. SBP was decreased significantly after administration of danshen extract in 2K1C, whereas plasma renin activity (PRA) was not changed. The plasma concentration of aldosterone (PAC) was decreased significantly in 2K1C group administered with Danshen extract, whereas the plasma concentration of ANP was increased by administration of danshen extract for three weeks. These results suggest that danshen has an anti-hypertensive effect through the inhibition of ACE, an essential regulatory enzyme of RAS.     

红丝线提取物对肾性高血压大鼠血压、一氧化氮和内皮素的影响

目的：观察红丝线提取物对肾性高血压大鼠血压、尿和血清中一氧化氮、一氧化氮合酶及内皮素浓度的影响。方法：采用两肾-夹高血压大鼠模型，连续灌胃给药4周，并于每周末测定血压；给药第4周末留尿测定尿-氧化氮含量，并处死动物取血测血清一氧化氮、一氧化氮合酶及内皮素的浓度变化。结果：红丝线灌胃1周后能使肾性高血压大鼠血压明显下降，血清中一氧化氮合酶以及尿和血清中一氧化氮浓度明显升高，而血浆中内皮素浓度明显降低。作用持续四周。结论：红丝线能降低肾性高血压大鼠的血压，升高一氧化氮合酶以及尿和血清中一氧化氮浓度，降低血浆中内皮素浓度。     

Effect of garlic (Allium sativum L.) extract on tissue lead level in rats.

The prophylactic efficacy of garlic (Allium sativum L.) extract to reduce tissue lead (Pb) concentration was evaluated experimentally in rats. Thirty female rats were divided into five groups, keeping group A as a healthy control. Rats of groups B, C, D and E received lead acetate orally at the rate of 5 mg per kg body weight daily for 6 weeks. The garlic extract was tried in three doses, viz. 100 (low), 200 (medium) and 400 mg (high) per kg body weight orally and given simultaneously with lead salt to the rats of group C, D and E, respectively. Mean blood lead concentrations in lead-exposed rats ranged between 0.13+/-0.02 and 0.96+/-0.06 microg/ml, whereas in garlic-treated rats, the range was between 0.16+/-0.01 and 0.80+/-0.05; 0.13+/-0.01 and 0.71+/-0.06 and 0.14+/-0.01 and 0.60+/-0.05 microg per ml in low, medium and high dose groups, respectively. The mean lead concentration in liver, kidneys, brain and bone of lead exposed rats was 2.943+/-0.206, 4.780+/-0.609, 1.019+/-0.100 and 44.075+/-2.60 microg per ml, respectively. Concomitant use of garlic extract at the three different doses was found to reduce lead concentration considerably indicating the potential therapeutic activity of garlic against lead.     

黑加仑籽粉对肾性高血压大鼠血压的影响

目的：探讨黑加仑籽粉对肾性高血压大鼠血压和血浆内皮素-1（endothelin-1, ET-1）、血清一氧化氮（ nitric oxide, NO）、超氧化物歧化酶（ superoxide dismutase, SOD）、丙二醛（ malonic di-aldehyde, MDA）的影响。方法将实验SD雄鼠随机分为假手术组、模型组、卡托普利组、黑加仑籽粉组,灌胃给药8周,假手术组、模型组给予等容量蒸馏水,于给药前及给药后定期对SD大鼠血压进行测量,并对给药8周后SD大鼠血浆中的ET-1含量,血清中的SOD活力、NO及MDA含量进行测定。结果给药8周后,与假手术组相比,模型组的血压、血浆中ET-1含量、血清中MDA的含量均明显升高（ P〈0．01）,且血清中NO含量及SOD活力明显降低（ P〈0．01或P〈0．05）;与模型组相比,卡托普利组、黑加仑籽粉组的血压明显下降（P〈0．01）,血浆中ET-1含量及血清中MDA的含量均明显降低（P〈0．01）,血清中 NO的含量明显升高（P〈0．01）,SOD活力无显著性差异（P〉0．05）。结论黑加仑籽粉对肾性高血压大鼠具有降压作用,推测其作用途径可能与通过抗氧化作用来保护血管内皮细胞,改善血管内皮功能有关。     

Antihypertensive effect of total flavone extracts from Puerariae Radix

Aim of the study

To evaluate the antihypertensive effect of total flavone extracts from Puerariae Radix (FEPR). To explore the hemodynamic profiles and pertinent mechanism of the extracts.

Materials and methods

Acute and chronic antihypertensive effects of FEPR were examined in spontaneous hypertensive rats (SHRs) and reno-hypertensive rats (two kidneys one clip model, 2K1C). Anesthetized dogs were used to evaluate the hemodynamic effects of FEPR. The determination of angiotensin converting enzyme (ACE) activity in vitro and plasma renin activity (PRA) and endothelin (ET) in vivo were used to study the pilot mechanism of FEPR. Moreover, the toxicity study of FEPR was evaluated.

Results

FEPR (100, 200 and 400 mg/kg, i.v.) notably reduced the blood pressure of SHRs in a short time period. A two-week administration of FEPR (45, 90 and 180 mg/kg, p.o.) decreased the blood pressure of both 2K1C rats and SHRs. The results of hemodynamic study in anesthetized dogs showed that, left ventricular end systolic pressure and left ventricular dP/dt_max had shown no significant difference between FEPR-treated dogs and those from the control group, while the cerebral blood flow increased significantly in FEPR-treated groups. FEPR significantly inhibited the ACE activities in vitro dose dependently, and inhibited the PRA in vivo, while the content of ET showed no difference in the FEPR treated group comparing with the control group.

Conclusions

FEPR shows significantly blood pressure lowering and cerebral vascular resistance (CVR) decreasing effect, which can partly be explained by the involvement of the Renin-Angiotensin-System (RAS).     

L-精氨酸对肾性高血压大鼠主动脉肥厚及组织局部RAS的影响

 目的探讨一氧化氮前体L-精氨酸对肾血管性高血压大鼠主动脉肥厚及组织局部肾素-血管紧张素系统(RAS)的影响。方法采用两肾一夹型肾血管性高血压大鼠模型。所有大鼠被随机分为4组(每组10只):假手术对照组;高血压对照组;L-精氨酸治疗组,于术后第5周开始给予L-精氨酸200mg·kg^-1·d^-1;L-NAME处理组,于术后第5周开始同时给予L-NAME10mg·kg^-1·d^-1及L-精氨酸200mg·kg^-1-1。采用标准尾套法间接检测清醒大鼠血压。给药8周后,大鼠处死,分离其胸主动脉以用于检测胸主动脉的血管紧张素Ⅱ含量(放射免疫法检测)、血管紧张素转化酶活性(分光光度计法检测)和胸主动脉中膜厚度及中膜截面积。结果与假手术组大鼠相比,未给药两肾一夹(2K1C)高血压大鼠血压明显升高,胸主动脉的血管紧张素Ⅱ含量增加和血管紧张素转化酶活性增高,主动脉中膜厚度及中膜截面积明显增大。应用L-精氨酸治疗则明显抑制了肾动脉狭窄术后大鼠血压的升高,降低了2K1C高血压大鼠胸主动脉的血管紧张素Ⅱ含量和血管紧张素转化酶活性,并减小了主动脉中膜厚度及中膜截面积。一氧化氮酶抑制剂L-NAME明显抑制了L-精氨酸的上述作用。结论长疗程L-精氨酸治疗可抑制肾性高血压大鼠主动脉肥厚的发生,其机制可能与抑制主动脉组织局部血管紧张素Ⅱ生成有关。     

Effects of aqueous extracts of Apocynum venetum leaves on spontaneously hypertensive, renal hypertensive and NaCl-fed-hypertensive rats

Effects of aqueous extracts of Apocynum venetum leaves (Luobuma extracts) on the blood pressure were evaluated in hypertensive animal models, such as spontaneously hypertensive rats (SHR), renal hypertensive rats and NaCl-induced hypertensive rats. In SHR, administration of Luobuma (heat-processed and unprocessed leaves) extracts at a dose of 70 mg/rat per day significantly decreased the systolic blood pressure value, but their decreasing effects were weaker than that of captopril. The urine volume, and the urinary Na(+), K(+) and protein excretions were not significantly different between Luobuma-treated and untreated groups. In 3/4 nephrectomized rats, the Luobuma extracts significantly decreased the systolic blood pressure value, accompanied by significant increases of the urine volume and the urinary Na(+) and K(+) excretions. Furthermore, they decreased the blood urea nitrogen (BUN) level. In NaCl-induced hypertensive rats, the Luobuma extract decreased the systolic blood pressure value. However, it did not change the urinary excretions of Na(+), K(+) and protein. The BUN level was lower than that of control rats, but the serum total cholesterol (TC) level did not changed. From these findings, the Luobuma extracts have an anti-hypertensive effect, possibly due to amelioration of the kidney functions in the three experimental animal models.     

两肾一夹型高血压大鼠模型的改良及评价

目的:采用Goldblatt经典肾性高血压大鼠模型并加以改进,建立简易稳定的两肾一夹型高血压大鼠模型.方法:将70只雄性SD大鼠,随机分为模型组和假手术组,其中模型组大鼠从背部开口以丝线结扎左肾动脉,假手术组大鼠除不结扎左肾动脉,余步骤同模型组.术后测定4周内不同时间点血压及观察一般情况对所建模型进行评价.结果:模型组术后成活率达94.5％,成模率达89.1％模型组大鼠自造模后3d血压开始升高,此后呈持续性升高,与实验前和假手术组比较均保持显著性差异(P＜0.05).结论:从背部开口以丝线结扎大鼠左肾动脉是一种安全性高和手术操作简便的新方法.     

肾性高血压大鼠模型与自发性高血压大鼠的比较

目的：探讨肾性高血压大鼠模型与自发性高血压大鼠（SHR）之间的异同,为临床治疗继发性高血压和原发性高血压提供一定实验依据。方法：采用左肾动脉结扎的方法复制肾型高血压大鼠模型,筛选造模成功的大鼠6只设为模型组,随机选取SHR大鼠6只,平衡血压2周后设为SHR组,另以6只正常sD大鼠作为空白组。采用尾动脉无创测压法检测血压,每周1次,连续4周后,心脏超声检测心脏指标,荧光实时定量PCR技术检测肝脏血管紧张素转换酶（ACE）和内皮细胞（ET）mRNA的表达水平。结果：（1）肾性高血压大鼠造模成功;（2）与空白组比较,模型组的血压显著升高（P〈0．01）;与模型组比较,SHR大鼠血压明显升高（P〈0．01）。（3）通过检测各组大鼠心脏超声发现,肾性高血压大鼠及SHR大鼠LVDd、LVDs、LVPWd、LVPWs均增大,EF显著降低（P〈0．01）。且SHR大鼠LVDd、LVDs、LVPWd、LVPWs增大较肾性高血压大鼠更为明显（P〈0．01）,EF虽无统计学意义,但仍有降低趋势。（4）通过检测肝脏ET、ACEmRNA表达量发现,与空白组比较,模型组ACE、ETmRNA的表达量均明显升高（P〈0．01）;与模型组比较,SHR组ACE、ETmRNA的表达量明显升高（P〈0．01或P〈0．05）。结论：SHR大鼠较肾性高血压大鼠模型血压高、心功能低、缩血管作用明显。     

Effects of electroacupuncture at different points on colorectal distention-induced changes in blood pressure, electrogastrogram, gastric tension and gastric blood flow

Objective: To investigate the specificity of the effects of electroacupuncture (EA) at different acupoints on gastric functional activity and gastric blood flow after colorectal distension (CRD) in the rat.Methods: Fifty Wistar rats were randomly divided into 5 groups: a control group,a Zusanli group,a non-point group,a Taichong group and a Neiguan group.Rats were anesthetized after 18 h of fasting,and a rat model of nociceptive blood pressure elevation and abnormal electrogastrogram (EGG) and gastric tension (GT) was prepared by gasbag-induced CRD.EA was given bilaterally,and its effects on gastric blood flow (GBF) of the arcus vasculosi of the greater omentum,blood pressure,EGG fast wave properties,and gastric smooth muscle tension (GT) were quantified.Results: CRD induced an increase in blood pressure that was significantly inhibited by EA at all points (all P＜0.05),and the inhibitory effects were greater in the Zusanli and Neiguan groups compared to the non-point group (both P＜0.05).CRD also caused reductions in GT and GBF,and in the amplitude,frequency and duration of EGG waves (all P＜0.05).These effects were also reversed by EA.The effects of EA on EGG wave amplitude,GT,and GBF were superior in the Zusanli group compared to the Taichong group,Neiguan group,and the non-point group.Conclusion: EA significantly counteracted CRD-induced changes in blood pressure,GBF,EGG; and GT.The effects of stimulation at Zusanli (ST 36) were significantly greater compared to other points,indicating relative specificity of this acupoint.