Sympathetic modulation of renal hemodynamics,renin release and sodium excretion

Summary In anesthetized animals it has been shown previously, that the influence of electrical stimulation of efferent renal nerves on renal function with increasing stimulation frequencies can be graded; renin release is affected at low, sodium excretion at intermediate and vascular resistance at high stimulation frequencies.Experiments in conscious dogs are reviewed, which present evidence for a similar functional dissociation under physiological conditions.Moderate activations of the renal sympathetic nerves, which do not change renal blood flow 1) decrease sodium excretion independent of changes in angiotensin II, 2) interact with the pressure-dependent mechanism of renin release by resetting its threshold pressure and 3) modulate autoregulation by increasing the lower limits of glomerular filtration rate and renal blood flow-autoregulation.These findings may contribute to our understanding of the role of the renal nerves in the pathophysiology of congestive heart failure and hypertension.     

Hypotensive effects of captopril on physical properties of the arterial system in young and adult rats

We determined the acute effects of the angiotension converting enzyme inhibitor captopril on the arterial mechanics in rats at different ages, based on the exponentially tapered T-tube model. Male Wistar-Kyoto rats aged 4 and 12 months were individually referred to as young (n = 8) and adult rats (n = 8) and wereanesthetized and thoractomized. The pulsatile aortic pressure andflow signals before and after the administration of captopril (20mg/kg, i.p.) were measured by a high-fidelity pressure sensor andan electromagnetic flow probe, respectively. In each age group,captopril showed little change in basal heart rate as well ascardiac output. However, captopril produced a drop of 15% in meanaortic pressure in young and a fall of 12% in adult rats. Inaddition, captopril reduced total peripheral resistance by 21% inyoung and by 23% in adult animals. As for the pulsatile nature ofthe arterial system, captopril had increased wave transit time ofthe lower body circulation of 10% in young and of 12% in adultrats. By contrast, captopril reduced wave reflection factor by22% in young and by 25% in adult animals. In conclusion, theconverting enzyme inhibitor captopril has a stiffness-decreasingeffect on Windkessel vessels and a dilated effect on resistancearterioles in either young or adult rats. No age dependence ofvascular response and reflex tachycardia to captopril has beenfound in rats between 4 and 12 months.     

血管紧张素转换酶基因的插入/缺失多态性与冠心病关系的研究

运用ＰＣＲ技术对９５例冠心病（ＣＨＤ）患者和１００例健康人的血管紧张素转换酶（ＡＣＥ）基因插入／缺失多态性进行了检测，并与ＣＨＤ发病、血清ＡＣＥ水平、易患因素等指标进行比较。结果：ＣＨＤ组缺失等位基因Ｄ频率为０．５４，ＤＤ基因型频率为０．３５，显著高于对照组的０．３５和０．１３（均Ｐ＜０．０１）。表明ＡＣＥ基因的缺失多态性可能是我国人群ＣＨＤ发病的重要危险因素之一。     

豨莶草对肾性血管性高血压降压作用机制的研究

目的:探讨豨莶草对肾性高血压的降压作用,并对其降压机制进行研究.方法:采用两肾一夹法复制肾血管性高血压大鼠模型,随机分为模型组、卡托普利(25 mg·kg-1)组、豨莶草(高、中、低剂量)(64 g·kg-1、32 g· kg-1、16 g· kg-1)组,另设假手术组.连续给药4周后,检测大鼠尾动脉收缩压(systo...     

针刺曲池和太冲对高血压病不同证型的疗效

目的：观察针刺曲池、太冲穴治疗不同证型高血压病患者的临床疗效及对患者血中血管紧张素转换酶（ACE）和内皮素（ET）含量的影响；并探讨曲池、太冲穴针刺降压的作用机制。方法：将高血压病患者80例随机分为肝火亢盛、痰湿壅盛、阴虚阳亢与阴阳两虚四组。均运用针刺治疗。用放免法测定血浆ET含量和化学比色法测定血清ACE含量。结果：1个疗程后。痰湿壅盛组和肝火亢盛组降压疗效明显优于阴虚阳亢组和阴阳两虚组（P〈0．01），阴虚阳亢组和阴阳两虚组比较差异也有显著性意义（P〈0．01）。1个疗程后血浆中ET均有不同程度下降，下降的程度依次为痰湿壅盛组〉肝火亢盛组〉阴虚阳亢组〉阴阳两虚组；阴虚阳亢组、肝火亢盛组、痰湿壅盛组三组与治疗前比较，差异均有显著性意义（P〈0．01，P〈0．05）。血清ACE均有不同程度升高，依次为肝火亢盛组〉痰湿壅盛组〉阴虚阳亢组〉阴阳两虚组。阴虚阳亢、肝火亢盛、痰湿壅盛三组与治疗前比较，差异均有显著性意义（P〈0．01）。结论：高血压证型与病情的严重程度有关，针刺曲池、太冲可调节高血压病患者血中ACE、ET的含量。