Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis

Autosomal recessive renal tubular dysgenesis (RTD) is a severe disorder of renal tubular development characterized by early onset and persistent fetal anuria leading to oligohydramnios and the Potter sequence, associated with skull ossification defects. Early death occurs in most cases from anuria, pulmonary hypoplasia, and refractory arterial hypotension. The disease is linked to mutations in the genes encoding several components of the renin-angiotensin system (RAS): AGT (angiotensinogen), REN (renin), ACE (angiotensin-converting enzyme), and AGTR1 (angiotensin II receptor type 1). Here, we review the series of 54 distinct mutations identified in 48 unrelated families. Most of them are novel and ACE mutations are the most frequent, observed in two-thirds of families (64.6%). The severity of the clinical course was similar whatever the mutated gene, which underlines the importance of a functional RAS in the maintenance of blood pressure and renal blood flow during the life of a human fetus. Renal hypoperfusion, whether genetic or secondary to a variety of diseases, precludes the normal development/ differentiation of proximal tubules. The identification of the disease on the basis of precise clinical and histological analyses and the characterization of the genetic defects allow genetic counseling and early prenatal diagnosis.     

Hyperreactio luteinalis associated with chronic renal failure

Hyperreactio luteinalis is a rare benign condition characterized by bilateral ovarian enlargement associated with pregnancies where high concentrations of maternal serum human chorionic gonadotrophins are present. This condition may mimic the ovarian hyperstimulation syndrome. We report a case of a 34 year old woman with a history of chronic renal failure on haemodialysis who presented at 10 weeks' gestational age with hyperreactio luteinalis which was treated conservatively. Because of chronic renal failure, the presentation and course of the disease was different from that which has been previously reported.     

限盐对慢性肾衰大鼠的心脏蛋白质组的影响

目的构建低盐饮食条件下慢性肾衰大鼠的心脏蛋白质谱,探索限盐对慢性肾衰大鼠的心脏蛋白质组的影响。方法采用5／6肾切建立慢性肾衰大鼠模型,设为假手术组（Sham组,6只）和慢性肾衰组（CRF组,6只）,术后第10周低盐（0．02％NaCl）饮食干预14d,然后取心脏左室游离壁进行蛋白提取及酶解和肽段同位素标记相对和绝对定量技术（iTRAQ）标记,最后经毛细管高效液相色谱分离后用Q—Exactive质谱仪进行蛋白质质谱分析。结果运用iTRAQ技术对低盐饮食条件下慢性肾衰大鼠的心脏蛋白质组进行了研究,共鉴定了1833种蛋白,构建了心脏蛋白质谱;其中226种蛋白发生了差异性改变,主要具有结合、催化活性等生物功能,涉及代谢、转运、生物过程的调节、应激等。结论成功构建了低盐饮食条件下慢性肾衰大鼠的心脏蛋白质谱。     

Effects of hydralazine on renal sympathetic nerve activity in normal and congestive heart failure rats

We investigated the effects of hydralazine on renal sympathetic nerve activity in anaesthetized heart failure rats. Sham-operated rats (group 1) received 0.5 mg kg^?1 of hydralazine as bolus and were then infused with 0.3–0.5 mg kg^?1 h^?1 for 3 h intravenously. Heart failure rats received either the same regime (group 2) as group 1, or the same volume of vehicle (group 3). Heart failure rats exhibited lower mean blood pressure (P < 0.05) and elevated renal sympathetic nerve activity (P < 0.01) in the basal state. In group 2, the mean blood pressure decreased 26% after 30 min of hydralazine administration and remained lower for 3 h, with unchanged renal sympathetic nerve activity. In group 1, the mean blood pressure decreased 36%, and the heart rate and renal sympathetic nerve activity were significantly inhibited. Bilateral vagotomy did not alter renal sympathetic nerve response to hydralazine, but resulted in tachycardia. The results indicate that hydralazine, despite its profound hypotensive effect, did not activate renal sympathetic nerve activity in heart failure rats and inhibited renal sympathetic nerve activity in sham-operated rats. This inhibition was not mediated through the vagal nerve.     

慢性肾衰竭大鼠肾细胞外基质变化

目的:分析慢性肾衰竭大鼠肾去细胞组织结构特点,探讨慢肾衰大鼠肾细胞外基质的病理变化。方法:SD大鼠实验组腺嘌呤灌胃,行去细胞处理后,H-E、Masson染色及电镜观察慢肾衰大鼠肾形态学结构变化及去细胞支架的生物学特性,免疫荧光分析其细胞外基质成分的变化。结果:腺嘌呤灌胃造模组慢肾衰血尿素氮、血肌酐明显增高,肾大体显示透明度降低,且随灌胃时间延长,H-E染色整体支架更加粗大,同时细胞数目以及小管区结晶数目明显增多;Masson三色染色显示实验组肾支架可见大量蓝色的胶原纤维沉积;扫描电镜显示2组肾细胞外基质三维结构紊乱,细胞外胶原纤维更加致密且有不同程度的增生;进一步免疫荧光检测,显示实验组支架的层黏连蛋白、胶原蛋白Ⅰ及Ⅳ都有明显的绿色荧光表达。结论:慢性肾衰肾支架病理形态结构改变及细胞外基质增生,为进一步研究慢肾衰肾支架是否可作为复细胞支架提供依据。     

Cardiac sympathetic afferent reflex and its implications for sympathetic activation in chronic heart failure and hypertension

Persistent excessive sympathetic activation greatly contributes to the pathogenesis of chronic heart failure (CHF) and hypertension. Cardiac sympathetic afferent reflex (CSAR) is a sympathoexcitatory reflex with positive feedback characteristics. Humoral factors such as bradykinin, adenosine and reactive oxygen species produced in myocardium due to myocardial ischaemia stimulate cardiac sympathetic afferents and thereby reflexly increase sympathetic activity and blood pressure. The CSAR is enhanced in myocardial ischaemia, CHF and hypertension. The enhanced CSAR at least partially contributes to the sympathetic activation and pathogenesis of these diseases. Nucleus of the solitary tract (NTS), hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla are the most important central sites involved in the modulation and integration of the CSAR. Angiotensin II, AT₁ receptors and NAD(P)H oxidase‐derived superoxide anions pathway in the PVN are mainly responsible for the enhanced CSAR in CHF and hypertension. Central angiotensin‐(1‐7), nitric oxide, endothelin, intermedin, hydrogen peroxide and several other signal molecules are involved in regulating CSAR. Blockade of the CSAR shows beneficial effects in CHF and hypertension. This review focuses on the anatomical and physiological basis of the CSAR, the interaction of CSAR with baroreflex and chemoreflex, and the role of enhanced CSAR in the pathogenesis of CHF and hypertension.     

Glomerular structure in lithium-induced chronic renal failure in rats

The effects of long-term lithium administration on glomerular structure and intervention with angiotensin converting enzyme inhibitor (ACEI) were studied in rats. Male Wistar rats were fed a lithium-containing diet (Li) or control diet (C) for 16 weeks postnatally. Li-treated rats developed renal failure, hypertension and proteinuria. During the subsequent 24 weeks, subgroups were treated with ACEI. The kidneys were fixed by perfusion, and tissue blocks were serially cut for estimation of glomerular volume and glomerular characteristics by light microscopy. Mesangial and mesangial matrix volume fractions, surface density of capillary walls, basement membrane thickness and foot process width (FPW) were measured by electron microscopy. Glomerular volume was decreased in Li-rats, with increased intra-individual variation. In all Li-rats, some glomeruli (mean 27%) were abnormal, with severe changes in only three rats. Ultrastructural parameters obtained by systematic sampling of three glomeruli in each rat showed no differences among groups. Among Li-treated animals there was a significant correlation between FPW and albumin excretion per unit filtration surface, and between filtration surface per glomerulus and inulin clearance. In conclusion, long-term lithium administration to newborn rats caused marked changes in glomerular volume which were not associated with measurable changes in structural parameters. No effect of ACEI-treatment was detectable.     

Review article--involvement of gastric APUD cells in chronic renal failure

Uremia leads to a number of metabolic and hormonal disorders induced by renal failure with definite biological and clinical sequels. Most frequently, alimentary disorders are the first to appear, followed by symptoms from other organs and systems. The gastrointestinal tract is a site of synthesis of many compounds that have hormonal or hormonal-like biological activity. These substances are produced by highly-specialised receptor-effector cells, that are dispersed in the gastrointestinal mucosa and classified as APUD cells. The present review is an attempt to make a synthesis of current opinions and views concerning the effect of homeostatic dysfunction of the kidneys on the morphology and action of APUD cells in the stomach.     

Postnatal development of the renal medulla; role of the renin–angiotensin system

Adverse events during foetal development can predispose the individual for cardiovascular disease later in life, a correlation known as foetal programming of adult hypertension. The ‘programming’ events have been associated with the kidneys due to the significant role in extracellular volume control and long‐term blood pressure regulation. Previously, nephron endowment and functional consequences of a low nephron number have been extensively investigated without achieving a full explanation of the underlying pathophysiological mechanisms. In this review, we will focus on mechanisms of postnatal development in the renal medulla with regard to the programming effects. The renin–angiotensin system is critically involved in mammalian kidney development and impaired signalling gives rise to developmental renal lesions that have been associated with hypertension later in life. A consistent finding in both experimental animal models and in human case reports is atrophy of the renal medulla with developmental lesions to both medullary nephron segments and vascular development with concomitant functional disturbances reaching into adulthood. A review of current knowledge of the role of the renin–angiotensin system for renal medullary development will be given.     

慢性肾功能衰竭患者血液透析发生院内感染的临床分析

目的分析慢性肾功能衰竭患者血液透析发生院内感染的临床特点以及相关危险因素。方法回顾性分析2005年5月至2010年5月期间在我院长期行血液透析的383例患者的相关临床资料,将其中160例患者出现了不同程度的院内感染设为感染组,223例患者未出现院内感染为未感染组。结果血液透析患者发生院内感染的发生率为41.78%,其中以肺部感染最为常见;感染组与未感染组患者之间的相关临床指标相比较,年龄、住院天数、是否左心衰、是否有糖尿病、是否存在低蛋白血症、插管时间以及C反应蛋白具有统计学差异（P〈0.05或0.01）,而性别、血肌酐、甘油三脂不具有统计学差异（P〉0.05）。结论对于长期血液透析患者,我们应该控制好各个危险因素,规范化管理防治院内感染的相关制度,对患者采取正规的营养支持、纠正贫血、抗感染等支持治疗,及时的作相关病原学检查,严防滥用抗生素。     

Citrate attenuates vascular calcification in chronic renal failure rats

Vascular calcification (VC) is a major contributor of cardiovascular dysfunction in chronic renal failure (CRF). Citrate binds calcium and inhibits the growth of calcium crystals. This present study intends to evaluate the effect of citrate on VC in adenine‐induced CRF rats. The rats were randomly divided into five groups: the control group, the citrate control group, model group, model rats with low‐dose treatment of citrate (216 mg/kg) and model rats with high‐dose treatment of citrate (746 mg/kg). The rats were euthanized at 5 weeks with their blood and aorta in detection. The results showed that serum level of blood urea nitrogen, serum creatinine, phosphorus, calcium, and related renal failure function marker were elevated in the model group. Furthermore, the aortic calcium accumulation and alkaline phosphatase activity were significantly increased in the model group compared with control groups. Additionally, hematoxylin–eosin staining results demonstrated that the vascular calcification in aorta is significantly increased in the model group. Finally, the expression of VC‐related proteins including bone morphogenetic protein and osteocalcin were increased in the model group, whereas alpha‐smooth muscle actin was decreased in the model group compared with the control group. However, treatment with citrate caused a reversal effect of all the above events in a dose‐dependent manner. In conclusion, citrate may attenuate vascular calcification in adenine‐induced CRF rats.     

Enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with heart failure induced by adriamycin

Our previous studies have shown that the cardiac sympathetic afferent reflex is enhanced in rats with chronic heart failure(CHF) induced by coronary artery ligation and contributes to the over-excitation of sympathetic activity.We sought to determine whether sympathetic activity and cardiac sympathetic afferent reflex were enhanced in adriamycin-induced CHF and whether angiotensin II(Ang II) in the paraventricular nucleus(PVN) was involved in enhancing sympathetic activity and cardiac sympathetic afferent reflex.Heart failure was induced by intraperitoneal injection of adriamycin for six times during 2 weeks(15 mg/kg).Six weeks after the first injection,the rats underwent anesthesia with urethane and α-chloralose.After vagotomy and baroreceptor denervation,cardiac sympathetic afferent reflex was evaluated by renal sympathetic nerve activity and mean arterial pressure(MAP) response to epicardial application of capsaicin(1.0 nmol).The response of MAP to ganglionic blockade with hexamethonium in conscious rats was performed to evaluate sympathetic activity.The renal sympathetic nerve activity and cardiac sympathetic afferent reflex were enhanced in adriamycin rats and the maximum depressor response of MAP induced by hexamethonium was significantly greater in adriamycin rats than that in control rats.Bilateral PVN microinjection of angiotensin II(Ang II) caused larger responses of the cardiac sympathetic afferent reflex,baseline renal sympathetic nerve activity and MAP in adriamycin rats than control rats.These results indicated that both sympathetic activity and cardiac sympathetic afferent reflex were enhanced and Ang II in the PVN was involved in the enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with adriamycin-induced heart failure.     

Amlodipine-induced gingival hyperplasia in chronic renal failure: a case report

Amlodipine is a dihydropyridine calcium channel blocker that is used in the management of both hypertension and angina. Amlodipine induced side effects are headache, dizziness, edema, flushing, palpitations, and rarely gingival hyperplasia. The exact reason of amlodipine-induced gingival hyperplasia is not known. We presented a case with chronic renal failure (CRF) that developed gingival hyperplasia due to amlodipine use, which improved after ceasing the drug.     

海沙瑞林对慢性心力衰竭大鼠心交感神经重构的影响*

目的：探讨海沙瑞林对慢性心力衰竭（ CHF）大鼠心交感神经重构的影响。 方法： SD大鼠随机分为对照组（ Control 组）、假手术组（ Sham组）、心力衰竭组（ HF组）和海沙瑞林干预组（ HF+Hx 组）,应用冠状动脉结扎法制作CHF大鼠模型,HF+Hx 组大鼠连续4 周尾静脉注射海沙瑞林 100 μg·kg-1·d-1,其他3 组注射等量的生理盐水。超声心动图测量左心室功能;H-E 染色及Masson 染色观察各组大鼠心肌病理结构变化;免疫组织化学和免疫印迹检测脑钠肽（ BNP）、神经生长因子（ NGF）、酪氨酸羟化酶（TH）和生长相关蛋白43（ GAP43）表达。结果：海沙瑞林干预升高CHF大鼠左室射血分数,改善左心室功能,减轻HF组心肌损伤结构病理改变,降低心肌细胞内BNP 表达,增加NGF、TH和GAP43 表达,差异均具有统计学意义。 结论：CHF大鼠存在心交感神经重构,海沙瑞林通过改变心交感神经重构, 改善心功能和CHF的预后可能是其实现心保护的机制之一。     

Evaluation of the brain and kidney renin-angiotensin system and oxidative stress in neonatal handled rats

The aim of this study was to test the hypothesis that the renin‐angiotensin system (RAS) components, as well as the oxidative stress system, would respond to early environmental changes. Thus, we have evaluated the effects of neonatal handling on both brain and kidney RAS and oxidative stress. Pups were divided into two groups: nonhandled and handled. The procedure consisted of handling them for 1 min/day in the first 10 days of life. On days 1, 5, and 10, animals were killed by decapitation. Blood samples were collected and the brain and kidneys were removed. Renin, AT₁, and AT₂ mRNA expression were evaluated through RT‐PCR. Angiotensin II (ANG II) serum concentration was also measured. An increased ANG II concentration, brain and kidney AT₂ mRNA expression were demonstrated. The kidney mRNA AT₁ expression was decreased. There was also a kidney lipid peroxidation increase and a brain superoxide dismutase and catalase decrease. In conclusion, handling in the neonatal period induces the activation of the angiotensinergic system, as well as modulates its mRNA receptor expression. The oxidative stress balance system seems not to be involved. © 2011 Wiley Periodicals,Inc. Dev Psychobiol 54: 706–713, 2012.