油橄榄叶提取物对L-NAME诱导的大鼠高血压的降压作用

作者将油橄榄叶用80％(m/m)乙醇提取,再用专利方法精制得实验用提取物。HPLC分析显示该提取物含18％-26％的橄榄苦苷。对以NG-硝基-L-精氨酸甲酯(L-NAME)造成的Wistar大鼠高血压模型进行了以下实验。1)油橄榄叶提取物对高血压的预防作用。将大鼠随机分为5组,空白对照组     

辛伐他汀对自发性高血压大鼠的降压作用

目的 研究辛伐他汀对自发性高血压的降压作用.方法 将雄性SD大鼠60只随机分为正常对照组、复合喂养组和辛伐他汀治疗组,各20只,给予区别饲养后,观察其血压、心率、血脂与血管重构情况.结果 各组血压对比均有明显差异（P＜0.05）.复合喂养组的心率明显高于辛伐他汀组与正常对照组（P＜0.05）,辛伐他汀组心率与正常对照组比较,无明显差异（P＞0.05）.复合喂养组的总胆固醇和甘油三酯水平较其他两组有明显升高（P＜0.05）,但辛伐他汀组心率与正常对照组比较,无明显差异（P＞0.05）.各组中膜厚度对比都有明显差异（P＜0.05）,复合喂养组的血管内膜面积与总面积的比值明显缩小（P＜0.05）.结论 辛伐他汀不但具有调脂与降血压作用,而且对大鼠主动重构有明显抑制作用,从而影响动脉血管重构和粥样硬化过程.     

褐藻氨酸对肾性高血压大鼠的降压作用

目的：探讨褐藻氨酸的降压作用。方法：用肾外包扎法使大鼠形成肾性高血压模型。模型组分为高剂量组（300μg/kg），低剂量组（150mg/kg)，并设阳性对照组和阴性对照组，均行灌胃，每天1次，共20天。结果：低剂量组大鼠血压降低20．2％，高剂量组降低26．2％，与生理盐水组比较均有非常显性差异（P＜0．01）。结论：褐藻氨酸对肾性高血压大鼠具有降压作用。     

纵条矶海葵中的生物碱成分研究

目的对纵条矶海葵(Haliplanella luciae)进行生物碱成分的研究。方法采用包括HPLC在内的多种色谱方法进行分离纯化,应用多种波谱学方法,主要是MS、1H-NMR、13C-NMR和2DNMR,结合文献对照确定化合物的结构。结果从纵条矶海葵的甲醇提取物水溶性部位中分离鉴定了3个吲哚生物碱成分:tryp-toline(1),1-甲基四氢-β-咔啉(1-methyltetrahydro-β-carboline,2)和β-吲哚乙胺(tryptamine,3);以及1个嘌呤生物碱成分:2-甲基亚氨基-3-甲基-6-甲基氨基-9氢-嘌呤(2-methylimino-3-methyl-6-methylamino-9H-purine,4)。结论所有化合物均为首次从纵条矶海葵科中获得;吲哚、嘌呤类是该种海葵中生物碱成分的主要类型。     

尼群地平对实验性肾性高血压的降压作用及其机理

以尼群地平对实验性肾血管及肾实质性高血压大鼠进行治疗的结果表明,尼群地平具有良好的降压作用,降压效果与基础血压水平呈正相关。尼群地平对血浆肾素活性及内源性洋地黄样物质水平虽无明显影响,但可降低异常升高的醛固酮水平及促进心钠素释放。这可能是它降低肾性高血压的重要作用机理。     

褐藻氨酸对肾性高血压大鼠的降压作用

目的探讨褐藻氨酸的降压作用。方法用肾外包扎法使大鼠形成肾性高血压模型。模型组分为高剂量组(300μg/kg) ,低剂量组(150mg/kg) ,并设阳性对照组和阴性对照组 ,均行灌胃 ,每天1次 ,共20天。结果低剂量组大鼠血压降低20 2 % ,高剂量组降低26 2 % ,与生理盐水组比较均有非常显著性差异(P<0.01)。结论褐藻氨酸对肾性高血压大鼠具有降压作用     

富马酸左旋氨氯地平对大鼠自发性高血压的降压作用

目的探讨富马酸左旋氨氯地平对自发性高血压大鼠的血压影响。方法将自发性高血压大鼠随机分为试验组和对照组,分别给予富马酸左旋氨氯地平或氨氯地平1,2,4mg／kg,观察给药前和给药后大鼠的血压变化。结果与对照组比较,试验组大鼠的血压显著降低（P〈0．01）,且呈较好的剂量一效应关系。结论富马酸左旋氨氯地平对自发性高血压大鼠的血压有明显降低的作用。     

藤丹胶囊对自发性高血压大鼠的降压作用

目的　观察藤丹胶囊对清醒自发性高血压大鼠 (spontaneous hypertension rats,SHR)血压和心率的影响。方法　单次及连续 1 4d每天灌服藤丹胶囊 0 .3 ,1 ,3 g· kg-1(相当于生药 ) ,并设有效药物阳性对照组 ,观察各剂量组对血压与心率的改变及恢复情况。结果　单次灌服大鼠血压呈剂量相关性降低 ,约 3 h达峰效应 ,高剂量作用维持时间超过 48h,降压同时心率无明显改变。连续 1 4d用药血压亦呈剂量相关性降低 ,每天的血压下降未见明显改变 ,表明无耐药性 ;停药后血压缓慢恢复到给药前水平 ,表明无反跳现象。结论　藤丹胶囊对SHR有明显的降压作用 ,对心率无明显影响     

依那普利对实验性高血压的降压作用

用高血压实验模型研究了依那普利(1)的抗高血压作用。口服1或3 mg/kg 对二肾型高血压大鼠具降压作用;但一肾型高血压大鼠降压则需较高剂量。1对自发性高血压大鼠能显著降低血压。兔静注10.3mg/kg,100 min内血管紧张素Ⅰ的升压作用可被抑制。     

口服钙的降压作用

近来,一些医学研究证明,钙摄取量与血压值呈负相关关系,这就提示钙不会引起高血压,补充钙可纠正高血压。 1 钙摄取量与血压值 我们早就知道饮用水的硬度与心血管病的病死率密切相关。Mccarron等人经过大规模医学研究,再次阐明了钙摄取量与血压值的负相关关系。他通过对既往无高血压的10372人营养调查,发现一日钙摄取量300mg以下的人,其高血压患病率     

白川降压胶囊的慢性降压作用

目的研究白川降压胶囊(BC)对清醒大鼠的慢性降压作用。方法清醒大鼠尾动脉无创血压测定法。结果BC0.6,0.3,0.15gkg3个剂量组药后收缩压和舒张压均明显降低,药后血压呈锯齿状缓慢下降,从给药d5或d7开始与对照组比较有显著性意义(P<0.05或P<0.01),以后逐渐稳定。BC的降压作用有剂量依赖关系,降压作用强度不大于硝苯地平,但降压作用比硝苯地平稳,表现为BC在1d内的降压波动比硝苯地平小。结论BC能平稳降低自发性高血压大鼠血压。     

Antihypertensive property of a novel uricosuric diuretic,S-8666, in rats

The antihypertensive, diuretic, and toxicological effects of S-8666 were studied in rats. At doses of more than 60 mg/kg/day, p.o., S-8666 was antihypertensive in DOCA-salt hypertensive rats with a potency corresponding to 1/20 of that of trichlormethiazide. The antihypertensive effect was dose-dependent, and, at the higher doses, S-8666 had a more potent depressor effect than trichlormethiazide. The antihypertensive activity of S-8666 was shown predominantly by the S-(?)-enantiomer, with the R-(+)-enantiomer being only slightly active. A similar dose-dependent antihypertensive effect was shown by furosemide, tienilic acid, or indacrinone, but the therapeutic index (LD₅₀/minimum effective dose) of S-8666 was the highest among them. The acute diuretic and natriuretic effects of S-8666 after oral administration of 60–200 mg/kg to DOCA-salt hypertensive rats correlated well with its antihypertensive effect, although such diuretic and natriuretic effects in normotensive rats had no effect on blood pressure. S-8666, like trichlormethiazide, showed a prophylactic effect on the development of hypertension in DOCA-salt hypertensive rats, salt-loaded spontaneously hypertensive rats (SHR), and salt-loaded Dahl-S rats, though it was much less potent. Moreover, the combination of S-8666 with captopril in SHR enhanced the depressor effect of captopril like hydrochlorothiazide. These results indicate that S-8666 can be an effective nonthiazide diuretic for use as an antihypertensive agent.     

Effect of cross-fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat

1. The severity of hypertension displayed by adult spontaneously hypertensive rats (SHR) and Dahl (SS/Jr) rats can be reduced by 20-30 mmHg if the hypertensive pup is cross-fostered to a normotensive mother within the first 2 weeks of birth. In the SHR, at least, this blood pressure-lowering effect arises through programming of the neonatal kidney to excrete sodium more effectively. Thus, cross-fostering may only be effective in lowering pressure in salt-sensitive hypertensive strains. Accordingly, the aim of the present study was to determine whether cross-fostering is effective in lowering adult blood pressure in the salt-resistant New Zealand genetically hypertensive (GH) rat. 2. Genetically hypertensive and control normotensive (N) rat pups were reared by either their natural mothers or a foster mother of the opposite strain (NX and GHX). Blood pressure was tracked from the age of 6-18 weeks, at which time renal function was assessed using standard clearance techniques in anaesthetized rats. Renal function was also assessed in a separate group of young rats at 5-6 weeks of age. 3. Cross-fostered GHX rats had lower blood pressure than GH rats, but this difference was only apparent until 9 weeks. The NX rats had higher blood pressures than N rats, but again pressure converged at 10 weeks. Basal renal function did not differ between GH and GHX rats or between N and NX rats at either age. However, young GH rats had lower renal blood flow, glomerular filtration rate, urine output and sodium excretion than N rats. 4. These data show that cross-fostering is effective in lowering blood pressure in GH rats, albeit transiently. The kidneys do not appear to play a role, because renal function did not differ under the current experimental conditions between GH and GHX rats. However, the kidney may play a greater role in the onset of hypertension in the GH rat than previously thought.     

Inhibition of regional brain acetylcholine biosynthesis by clonidine in spontaneously hypertensive rats

Recent studies in this laboratory have demonstrated that clonidine, a centrally acting antihypertensive drug, can inhibit the function of central cholinergic neurons. We have also provided evidence for enhanced brain cholinergic activity in the spontaneously hypertensive rat (SHR). The purpose of this study was to determine whether the antihypertensive response to clonidine in the SHR could be correlated with a decrease in acetylcholine synthesis in several brain regions. Clonidine (30μg/kg, i.v.) produced a time-dependent reduction in blood pressure (BP) in unrestrained SHR's of 18/16 and 27/22 mmHg by 10 min and 100 min, respectively. The formation of ³H-acetylcholine in the brain following pulse injection of ³H-choline (20 μCi) into the lateral cerebral ventricle was employed as an estimate of the rate of acetylcholine synthesis. Clonidine produced a time-dependent inhibition of ³H-acetylcholine formation in several brain areas. For example, in the pons, ³H-acetylcholine formation was reduced by 21 and 44% at 10 min and 100 min following clonidine, respectively. Other brain regions to exhibit significant inhibition of cholinergic activity included the rostral and the caudal hypothalamus, medulla oblongata, thalamus-septum, and midbrain. The striatum exhibited the greatest ³H-acetylcholine formation in control animals; however, this activity was not affected by clonidine. These results are consistent with the ability of clonidine, at a clinically relevant dose, to elicit concomitantly an antihypertensive response and a marked inhibition of brain cholinergic activity in SHRs. This finding in conjunction with the results from several previous studies suggest that central cholinergic neurons participate in mediating the antihypertensive action of clonidine.     

Ketanserin stabilizes blood pressure in conscious spontaneously hypertensive rats

1. It has been demonstrated that blood pressure variability (BPV) is increased in hypertension and related to organ damage. It will be important to lower BPV in the treatment of hypertension. The present study was designed to investigate the effect of ketanserin, a 5-HT2A receptor antagonist with a weak alpha1-adrenoceptor blocking effect, on BPV in conscious spontaneously hypertensive rats (SHR). 2. It was found that ketanserin decreased blood pressure (BP) and BPV in SHR when administered intravenously (3 mg/kg, i.v.). Ketanserin decreased BPV, but not the BP level, when administered intracerebroventricularly (50 microg/rat, i.c.v.). 3. Prazosin, an alpha1-adrenoceptor antagonist, lowered BP but did not affect BPV when given either i.v. (0.5 mg/kg) or i.c.v. (30 microg/rat). Ritanserin (0.625 mg/kg, i.v.; 40 microg/rat, i.c.v.), a 5-HT2A receptor antagonist, decreased BPV only when administered i.c.v. and did not modify the BP level. 4. Ketanserin enhanced arterial baroreflex function in SHR when given either i.v. or i.c.v. 5. The stabilizing effect of ketanserin on BP was persistent when administered intragastrically. This administration route is similar to oral administration clinically. 6. It is concluded that ketanserin is an antihypertensive agent with an effect of reducing BPV. This effect is mainly mediated by central 5-HT2A receptors and is probably attributable to the restoration of arterial baroreflex function.     

Arterial baroreflex is not involved in salt preference in rats

1. One unusual and interesting feature of spontaneously hypertensive rats (SHR) is their salt preference. This behaviour is known to be independent of blood pressure. 2. Arterial baroreflex (ABR) function is impaired in SHR. Therefore, the present study was designed to explore the relationship between ABR function and salt preference in rats. 3. Twenty-seven SHR, aged 11 months, were used. Blood pressure and baroreflex sensitivity (BRS) were determined in conscious, freely moving SHR after the measurement of salt preference. It was found that BRS did not relate to the salt preference in these rats. 4. Another group of normotensive Sprague-Dawley rats, aged 10 weeks, underwent either sinoaortic denervation (SAD) or sham operation. Salt preference was determined before and 4 weeks after SAD. Sinoaortic denervation did not alter salt preference in normotensive rats. 5. It is concluded that ABR function does not influence the salt preference in rats.     

异钩藤碱的降压及血流动力学作用(英文)

在清醒正常血压大鼠,iv Isorhy2.5 mg/kg对BP及HR均无明显影响,iv5 mg/kg则使DAP和HR降低,但SAP无变化,剂量加大至10 mg/kg时,上述各项指标均明显降低。经十二指肠内给Isorhy10 mg/kg后20 min出现BP及HR降低,而20mg/kg剂量组于10 min开始出现BP及HR的进一步下降.Isorhy(10mg/kg和2 mg/kg,iv)亦能分别降低肾性高血压清醒大鼠和麻醉犬的BP。icv表明中枢不是降压作用的主要部位,在体条件下无α-受体和神经节阻断作用。Isorhy使清醒大鼠和麻醉犬的LVSP,dP/dt_(max),V_(max)等左室收缩性能指标短暂下降,而BP呈持久性降低。在麻醉犬给药后CO,CI,HR及LVWI下降的同时SV和SI不变,TPVR降低,反映心肌氧耗的TTI明显减少.结果提示Isorhy具有肯定的降压作用,其持续降压与扩张血管及减慢心率导致CO下降有关,而其负性肌力作用亦可能参与了早期的降压机理.Isorhy能减少心肌氧耗对高血压心肌劳损可能有保护意义。     

BLOOD PRESSURE, PLASMA AND PITUITARY PROLACTIN RESPONSES TO BROMOCRIPTINE IN NEW ZEALAND GENETICALLY HYPERTENSIVE AND NORMOTENSIVE RATS

1. The effects on blood pressure (BP), plasma and pituitary prolactin (PRL) of a 13 day intraperitoneal infusion of bromocriptine (BRC) delivered by osmotic minipump were investigated in genetically hypertensive rats (GHR) and their normotensive (NT) controls. 2. In the GHR, the mean BP in the BRC-treated group over the 13 day period of study was significantly lower than in the vehicle-treated group. In the NT rats, the mean BP in the BRC-treated group over the 13 day period was also significantly lower than in the vehicle-treated group. 3. Mean plasma PRL concentration in the GHR and NT rats were comparable. In the GHR, the mean plasma PRL concentration taken on day 13 was significantly lower in the BRC-treated group than in the vehicle-treated group. In the NT rats, the mean plasma PRL concentration taken on day 13 in the BRC-treated group was, however, not significantly different from that in the vehicle-treated group. 4. The mean pituitary PRL content was not significantly different in the GH and NT rats. There was a greater suppression of pituitary PRL content in the BRC-treated GHR than in the BRC-treated NT rats compared with their respective vehicle-treated groups. 5. The results raise the possibility that PRL may have an indirect role in the pathogenesis of the hypertension of the GHR.     

Beneficial effects of the combination of amlodipine and losartan for lowering blood pressure in spontaneously hypertensive rats

A combination of antihypertensive agents can better control blood pressure and reduce the number and severity of side effects than a monotherapy. Since both CCBs (calcium channel blockers) and ARBs (angiotensin II receptor type-1 blockers) are current and effective antihypertensive drugs, this study assessed the synergistic antihypertensive effects as well as the optimal combination ratio of these two drugs. Amlodipine (3 mg/kg) or losartan (30 mg/kg) alone or a combination of each drug at a ratio 1:10 and 1:20 was administered orally to spontaneously hypertensive rats (SHR). A four-week treatment of either 3 mg/kg amlodipine or 30 mg/kg losartan alone decreased the systolic blood pressure (SBP). However, their combination significantly lowered the SBP from the 3^rd week, and there was a positive correlation between this reduction in blood pressure and the improvement in arterial endothelium-dependent relaxation. In addition, the combination therapy (1:20) decreased both the cardiac mass and left ventricular weight to a greater extent than with either amlodipine or losartan alone. The collagen content in the cardiac tissue was also significantly lower after the 4-week combination therapy (1:10). These results suggest that the combined use of amlodipine and losartan might be more effective in treating hypertension than a monotherapy.     

Influence of chronic naloxone treatment on development of hypertension in the spontaneously hypertensive rat

Summary Chronic administration of naloxone by means of miniosmotic pumps retarded the development of hypertension in young spontaneously hypertensive rats (SHRs) in a dose-related manner. Abrupt termination of naloxone treatment resulted in acceleration in the rate of the blood pressure increase, while increasing the naloxone concentration further slowed the development of hypertension in SHRs. The heart rates of SHRs undergoing chronic naloxone treatment were generally lower than those of control SHRs. Naloxone had no influence upon the mean systeolic blood pressures or heart rates of normotensive Wistar-Kyoto control rats. These findings indicate that chronic naloxone treatment can alter the development of hypertension in the SHR.