Urinary cytokine profiles according to the site of blockade of the renin-angiotensin system in nephrectomized rats.

INTRODUCTION: It is still unknown how the pharmacological inhibition of the Renin Angiotensin System (RAS) impacts the levels of inflammation and fibrosis biomarkers. OBJECTIVE: This study sought to evaluate the effect of enalapril, candesartan and aliskiren on urinary levels of cytokines in a model of chronic kidney disease (CKD). METHODS: Male Wistar rats were submitted to surgical removal of ¾ of renal parenchyma to induce CKD (¾ nephrectomy), or subjected to sham surgery (control). Animals were then randomized into five groups: Sham surgery receiving vehicle; ¾ Nephrectomy receiving vehicle; ¾ Nephrectomy receiving enalapril (10 mg/kg); ¾ Nephrectomy receiving candesartan (10 mg/kg) and ¾ Nephrectomy receiving aliskiren (10 mg/kg). Urine output, water intake, mean arterial pressure (MAP) and urinary concentrations of creatinine, urea, albuminuria, Na+, K+, interleukin (IL) -1ß, IL-6, IL-10 and transforming growth factor beta (TGF-ß) were measured. RESULTS: Nephrectomy significantly impaired renal function, increased MAP and altered the levels of all evaluated cytokines in urine. Enalapril, candesartan and aliskiren improved renal function and decreased MAP and IL-6 when compared to vehicle-treated nephrectomized group. Candesartan and aliskiren decreased IL-1ß, while only candesartan reduced TGF-ß and only aliskiren increased IL-10. CONCLUSION: Enalapril, candesartan and aliskiren presented similar effects on improving renal function and reducing MAP and urinary levels of IL-6 in rats with CKD. On the other hand, cytokine profile differed according to the treatment, suggesting that differential mechanisms were triggered in response to the site of RAS blockade.

Urinary cytokine profiles according to the site of blockade of the renin-angiotensin system in nephrectomized rats / Perfil de citocinas urinárias de acordo com o local de bloqueio do sistema renina angiotensina em ratos nefrectomizados

Abstract Introduction: It is still unknown how the pharmacological inhibition of the Renin Angiotensin System (RAS) impacts the levels of inflammation and fibrosis biomarkers. Objective: This study sought to evaluate the effect of enalapril, candesartan and aliskiren on urinary levels of cytokines in a model of chronic kidney disease (CKD). Methods: Male Wistar rats were submitted to surgical removal of ¾ of renal parenchyma to induce CKD (¾ nephrectomy), or subjected to sham surgery (control). Animals were then randomized into five groups: Sham surgery receiving vehicle; ¾ Nephrectomy receiving vehicle; ¾ Nephrectomy receiving enalapril (10 mg/kg); ¾ Nephrectomy receiving candesartan (10 mg/kg) and ¾ Nephrectomy receiving aliskiren (10 mg/kg). Urine output, water intake, mean arterial pressure (MAP) and urinary concentrations of creatinine, urea, albuminuria, Na+, K+, interleukin (IL) -1β, IL-6, IL-10 and transforming growth factor beta (TGF-β) were measured. Results: Nephrectomy significantly impaired renal function, increased MAP and altered the levels of all evaluated cytokines in urine. Enalapril, candesartan and aliskiren improved renal function and decreased MAP and IL-6 when compared to vehicle-treated nephrectomized group. Candesartan and aliskiren decreased IL-1β, while only candesartan reduced TGF-β and only aliskiren increased IL-10. Conclusion: Enalapril, candesartan and aliskiren presented similar effects on improving renal function and reducing MAP and urinary levels of IL-6 in rats with CKD. On the other hand, cytokine profile differed according to the treatment, suggesting that differential mechanisms were triggered in response to the site of RAS blockade.

Resumo Introdução: Ainda não se sabe como a inibição farmacológica do Sistema Renina Angiotensina (SRA) afeta os níveis de biomarcadores de inflamação e fibrose. Objetivo: Este estudo pretendeu avaliar o efeito de enalapril, candesartan e alisquireno sobre os níveis urinários de citocinas em um modelo de doença renal crônica (DRC). Métodos: Ratos Wistar machos foram submetidos à remoção cirúrgica de ¾ do parênquima renal para induzir DRC (nefrectomia), ou submetidos à cirurgia fictícia (controle). Animais foram então randomizados em cinco grupos: Cirurgia fictícia recebendo veículo; Nefrectomia recebendo veículo; Nefrectomia recebendo enalapril (10 mg/kg); Nefrectomia recebendo candesartan (10 mg/kg) e Nefrectomia recebendo alisquireno (10 mg/kg). Débito urinário, ingesta hídrica, pressão arterial media (PAM) e concentrações urinárias de creatinina, ureia, albumina, Na+, K+, interleucina (IL) -1β, IL-6, IL-10 e fator de transformação e crescimento beta (TGF-β) foram medidas. Resultados: A nefrectomia comprometeu significativamente a função renal, aumentou a PAM e alterou os níveis de todas as citocinas avaliadas na urina. Enalapril, candesartan e alisquireno melhoraram a função renal e diminuíram a PAM e a IL-6 quando comparado aos grupo de animais nefrectomizados tratados com veículo. Candesartan e alisquireno reduziram IL-1β, enquanto somente candesartan diminuiu o TGF-β e somente alisquireno aumentou a IL-10. Conclusão: Enalapril, candesartan e alisquireno apresentaram efeitos similares em relação à melhora da função renal e redução da PAM e dos níveis urinários de IL-6 em ratos com DRC. Por outro lado, o perfil de citocinas diferiu de acordo com o tratamento, sugerindo que diferentes mecanismos sejam desencadeados em resposta ao local de bloqueio do SRA.

Characterization of an experimental model of progressive renal disease in rats.

PURPOSE:: To characterize an experimental model of progressive renal disease induced by different degrees of nephrectomy in rats. METHODS:: Eighty male Wistar rats were divided into four experimental groups (n=20/group): sham surgery (control group), progressive degrees of nephrectomy leading to mild uremia (group 1), moderate uremia (group 2) and severe uremia (group 3). Ten animals of each group were followed for two or four weeks. At the end, blood and 24-hour urine samples were collected to determine renal function parameters. Urine output and water and food intake were daily monitored. RESULTS:: In rats of group 1, serum levels of creatinine and urea and microalbuminuria were increased, while reduced creatinine clearance (p<0.05, compared with control group), without changing blood pressure. Animals of group 2 had more accentuated alterations: increases in urinary output, blood pressure, serum concentrations of urea, creatinine, sodium, potassium, and in microalbuminuria, and reduction of creatinine clearance (p<0.05). Group 3 exhibited even more increased serum concentrations of urea, creatinine, sodium and potassium, blood pressure and microalbuminuria, and decreased creatinine clearance (p<0.05) in comparison with control group and unilateral nephrectomy. CONCLUSION:: Progressive nephrectomy in rats seems to be useful to study the physiopathology of chronic kidney disease and its mechanisms of progression.

Characterization of an experimental model of progressive renal disease in rats

ABSTRACT PURPOSE: To characterize an experimental model of progressive renal disease induced by different degrees of nephrectomy in rats. METHODS: Eighty male Wistar rats were divided into four experimental groups (n=20/group): sham surgery (control group), progressive degrees of nephrectomy leading to mild uremia (group 1), moderate uremia (group 2) and severe uremia (group 3). Ten animals of each group were followed for two or four weeks. At the end, blood and 24-hour urine samples were collected to determine renal function parameters. Urine output and water and food intake were daily monitored. RESULTS: In rats of group 1, serum levels of creatinine and urea and microalbuminuria were increased, while reduced creatinine clearance (p<0.05, compared with control group), without changing blood pressure. Animals of group 2 had more accentuated alterations: increases in urinary output, blood pressure, serum concentrations of urea, creatinine, sodium, potassium, and in microalbuminuria, and reduction of creatinine clearance (p<0.05). Group 3 exhibited even more increased serum concentrations of urea, creatinine, sodium and potassium, blood pressure and microalbuminuria, and decreased creatinine clearance (p<0.05) in comparison with control group and unilateral nephrectomy. CONCLUSION: Progressive nephrectomy in rats seems to be useful to study the physiopathology of chronic kidney disease and its mechanisms of progression.

Current knowledge on esophageal atresia.

Esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) is the most common congenital anomaly of the esophagus. The improvement of survival observed over the previous two decades is multifactorial and largely attributable to advances in neonatal intensive care, neonatal anesthesia, ventilatory and nutritional support, antibiotics, early surgical intervention, surgical materials and techniques. Indeed, mortality is currently limited to those cases with coexisting severe life-threatening anomalies. The diagnosis of EA is most commonly made during the first 24 h of life but may occur either antenatally or may be delayed. The primary surgical correction for EA and TEF is the best option in the absence of severe malformations. There is no ideal replacement for the esophagus and the optimal surgical treatment for patients with long-gap EA is still controversial. The primary complications during the postoperative period are leak and stenosis of the anastomosis, gastro-esophageal reflux, esophageal dysmotility, fistula recurrence, respiratory disorders and deformities of the thoracic wall. Data regarding long-term outcomes and follow-ups are limited for patients following EA/TEF repair. The determination of the risk factors for the complicated evolution following EA/TEF repair may positively impact long-term prognoses. Much remains to be studied regarding this condition. This manuscript provides a literature review of the current knowledge regarding EA.

Urinary chemokines and anti-inflammatory molecules in renal transplanted patients as potential biomarkers of graft function: a prospective study.

PURPOSE: Clinical- and histopathology-based scores are the limited predictors of allograft outcome. Thus, predictors of allograft survival still remain a challenge. This study aimed to evaluate the urinary levels of chemokines and anti-inflammatory molecules at 30, 90, and 300 days after renal transplantation and to further correlate these measurements to graft function. METHODS: Glomerular filtration rate (GFR) and urinary levels of MCP-1/CCL2, MIP-1α/CCL3, RANTES/CCL5, IL-8/CXCL8, IP-10/CXCL10, interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor-1, and receptor-2 were determined at 30, 90, and 300 days after renal transplantation in 22 patients. Transplanted patients were also divided according to the type of donor (living donor, LD, n = 13 or deceased donor, DD, n = 9). RESULTS: Urinary levels of all molecules, except MIP-1α/CCL3, remained unchanged at 30, 90, and 300 days after transplantation in our 22 patients. MIP-1α/CCL3 levels significantly reduced from 30 to 300 days and showed a negative correlation with GFR at 30 days. The comparison between LD and DD groups showed similar levels of all markers, except for MCP-1/CCL2, which presented higher values in LD than in DD at 30 days. sTNFR1 and MCP-1/CCL2 significantly reduced from 30 to 300 days in LD group, but only sTNFR2 concentrations at 30 days were negatively correlated with GFR at 300 days. On the other hand, in DD group, IL-1Ra concentrations at 30 and at 90 days were positively correlated with GFR at 300 days. CONCLUSION: Urinary chemokine and anti-inflammatory molecules measurements may be a promising tool in the follow-up of renal transplanted patients.

Renin-angiotensin system in the pathogenesis of liver fibrosis.

Hepatic fibrosis is considered a common response to many chronic hepatic injuries. It is a multifunctional process that involves several cell types, cytokines, chemokines and growth factors leading to a disruption of homeostatic mechanisms that maintain the liver ecosystem. In spite of many studies regarding the development of fibrosis, the understanding of the pathogenesis remains obscure. The hepatic tissue remodeling process is highly complex, resulting from the balance between collagen degradation and synthesis. Among the many mediators that take part in this process, the components of the Renin angiotensin system (RAS) have progressively assumed an important role. Angiotensin (Ang) II acts as a profibrotic mediator and Ang-(1-7), the newly recognized RAS component, appears to exert a counter-regulatory role in liver tissue. We briefly review the liver fibrosis process and current aspects of the RAS. This review also aims to discuss some experimental evidence regarding the participation of RAS mediators in the pathogenesis of liver fibrosis, focusing on the putative role of the ACE2-Ang-(1-7)-Mas receptor axis.

Relationship between angiotensin-(1-7) and angiotensin II correlates with hemodynamic changes in human liver cirrhosis.

AIM: To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system (RAS) components and hemodynamic changes. METHODS: Patients were allocated into 4 groups: mild-to-moderate liver disease (MLD), advanced liver disease (ALD), patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity (PRA), angiotensin (Ang) I, Ang II, and Ang-(1-7) levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components. RESULTS: PRA and angiotensins were elevated in ALD when compared to MLD and controls (P < 0.05). In contrast, Ang II was significantly reduced in MLD. Ang-(1-7)/Ang II ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang II levels were lower and Ang-(1-7)/Ang II ratios were higher in the splanchnic circulation than in the peripheral circulation (0.52 +/- 0.08 vs 0.38 +/- 0.04, P < 0.02), whereas the peripheral circulating Ang II/Ang I ratio was elevated in comparison to splanchnic levels (0.18 +/- 0.02 vs 0.13 +/- 0.02, P < 0.04). Ang-(1-7)/Ang II ratios positively correlated with cardiac output (r = 0.66) and negatively correlated with systemic vascular resistance (r = -0.70). CONCLUSION: Our findings suggest that the relationship between Ang-(1-7) and Ang II may play a role in the hemodynamic changes of human cirrhosis.

The renin-angiotensin system and diabetes: an update.

In the past few years the classical concept of the renin-angiotensin system (RAS) has experienced substantial conceptual changes. The identification of the renin/prorenin receptor, the angiotensin-converting enzyme homologue ACE2 as an angiotensin peptide processing enzyme, Mas as a receptor for Ang-(1-7) and the possibility of signaling through ACE, have contributed to switch our understanding of the RAS from the classical limited-proteolysis linear cascade to a cascade with multiple mediators, multiple receptors, and multi-functional enzymes. In this review we will focus on the recent findings related to RAS and, in particular, on its role in diabetes by discussing possible interactions between RAS mediators, endothelium function, and insulin signaling transduction pathways as well as the putative role of ACE2-Ang-(1-7)-Mas axis in disease pathogenesis.

Hipertensão arterial em crianças e adolescentes / Arterial hipertension in children and adolescents

A hipertensão arterial em pediatria é definida por níveis pressóricos iguais ou superiores ao percentil 95 para idade, sexo e estatura após três medidas sucessivas de pressão arterial (PA), tomadas pelo mesmo examinador em visitas diferentes, utilizando-se equipamento e técnica adequados. Embora a pressão arterial predomine na idade adulta, sua prevalência em criança e adolescentes não é desprezível, variando de 1,20 a 13% nos diversos estudos nacionais e internacionais. Neste artigo de revisão são abordados aspectos gerais de hipertensão arterial em crianças e adolescentes (definição, classificação, etiologia), sua abordagem diagnóstica e terapêutica e suas complicações.

The renin-angiotensin system in a rat model of hepatic fibrosis: evidence for a protective role of Angiotensin-(1-7).

BACKGROUND/AIMS: The circulating renin-angiotensin system (RAS) [plasma renin activity (PRA), Angiotensin (Ang) I, Ang II and Ang-(1-7)] was evaluated in a model of hepatic fibrosis in rats. To investigate the pathophysiological involvement of Ang-(1-7), animals were treated with the Ang-(1-7) Mas receptor antagonist, A-779. METHODS: RAS components, liver function and histology were examined in male Wistar rats (220-300 g). Animals were submitted to sham-surgery or ligature of the bile duct and evaluated 1, 2, 4 and 6 weeks later. Blood samples were obtained to determine biochemical parameters and RAS components. A second group was treated with A-779 or vehicle to measure liver hydroxyproline and total transforming growth factor beta-1 (TGFbeta1). RESULTS: PRA and Ang I were significantly elevated in rats at 4 and 6 weeks compared to sham-operated animals. Ang II and Ang-(1-7) progressively increased over the 6 weeks. Changes in RAS profile correlated with histological signs of fibrosis and deterioration in liver function. Pharmacological blockade of the Ang-(1-7) receptor aggravated liver fibrosis with a significant elevation in hydroxyproline and total TGFbeta(1). CONCLUSIONS: Hepatic fibrosis was associated with RAS activation in our model. Our data also suggested that Ang-(1-7) played a protective role in hepatic fibrosis.

Efeitos da acidose metabólica sobre o tecido ósseo: evidÛncias clínicas e experimentais / Effects of metabolic acidosis on the bone: clinical evidence and experimentai

A acidose metabólica é considerada um componente comum a diversas doenþas. Inúmeros estudos descreveram a participaþÔo do tecido ósseo na manutenþÔo da homeostase ácido básica. Entretanto, os efeitos do tamponamento ósseo sobre o osso propriamente dito nÔo estÔo bem estabelecidos. A acidose metabólica altera a composiþÔo do osso através de aþÔo fisico química direta, além de estimular a reabsorþÔo óssea mediada por células. Este artigo revisa algumas evidÛncias experimentais e clínicas sobre a participaþÔo do osso como sistema de tamponamento dos distúrbios do equilibrio ácido básico. Os efeitos que o osso, agindo como tampÔo, exerce sobre sua própria composiþÔo celular e estrutura também sÔo discutidos.(AU)

Efeitos da acidose metabólica sobre o tecido ósseo: evidências clínicas e experimentais / Effects of metabolic acidosis on the bone: clinical evidence and experimentai

A acidose metabólica é considerada um componente comum a diversas doenças. Inúmeros estudos descreveram a participaçâo do tecido ósseo na manutençâo da homeostase ácido básica. Entretanto, os efeitos do tamponamento ósseo sobre o osso propriamente dito nâo estâo bem estabelecidos. A acidose metabólica altera a composiçâo do osso através de açâo fisico química direta, além de estimular a reabsorçâo óssea mediada por células. Este artigo revisa algumas evidências experimentais e clínicas sobre a participaçâo do osso como sistema de tamponamento dos distúrbios do equilibrio ácido básico. Os efeitos que o osso, agindo como tampâo, exerce sobre sua própria composiçâo celular e estrutura também sâo discutidos.

The therapeutic potential of Angiotensin-(1-7) as a novel Renin-Angiotensin System mediator.

In this review, we show Angiotensin-(1-7) as a novel Renin Angiotensin System mediator that antagonizes cardiovascular and proliferative effects of Angiotensin II and exerts complex renal actions. We also speculate the possibility of new drugs for the treatment of cardiovascular, genitourinary and hepatic diseases by interfering with ACE2-Angiotensin-(1-7)-Mas axis.

Successful management of concomitant omphalocele, accessory hepatic lobe, and biliary atresia in a 44-day-old boy.

We report the second case in literature of a boy with the association of large omphalocele, accessory hepatic lobe, and biliary atresia, and the first successful treatment. The patient was submitted to a surgical treatment at 44 days of life, including Kasai procedure, correction of the remnant abdominal wall defect, and removal of a hepatic accessory lobe. The boy evolved with normalization of hepatic function tests. After 15 years of follow-up, the patient is completely healthy, weights 45 kg, and is 1.64 m tall.

Papel de mediadores endógenos na fisiopatologia da cirrose hepática / The role of endogenous mediators in the pathophysiology of hepatic cirrhosis

A cirrose hepática é o evento final das doenças hepáticas crônicas em pacientes adultos e pediátricos. Apesar de muitos estudos em relação ao desenvolvimento da fibrose hepática, o entendimento de sua etiopatogênese e fisiopatologia continua obscuro. Diversos mediadores, tais como componentes do sistema renina-angiotensina, o sistema nervoso simpático, a vasopressina, os peptideos natriuréticos, o sistema calicreína-cinina, a endotelina e o óxido nítrico podem estar envolvidos nesses mecanismos. Além disso, a abordagem terapêutica dos pacientes hepatopatas ainda é bastante limitada, contribuindo para o prognóstico reservado. Este artigo de revisão pretende discutir algumas evidências clínicas e experimentais relativas à participação destes mediadores endógenos na fisiopatologia da cirrose hepática.

The hepatic cirrhosis is the final event of many chronic hepatic diseases in adult and pediatric patients. In spite of many studies regarding the development of fibrosis, the understanding of its etio- and physiopathology remains obscure. Several mediators may be involved in these mechanisms: renin-angiotensin system, sympathetic nervous system, vasopressin, natriuretic peptides, kallicreinkynin system, endothelin, and nitric oxide. Furthermore, the therapeutic approach of the patients with chronic hepatic diseases is still limited, contributing to a bad outcome. Some clinical and experimental evidences regarding the participation of these endogeneous mediators in the physiopathology of hepatic cirrhosis are discussed.

Associaçäo entre inibidores de protease e urolitíase / Indinavir associated nephrolithiasis

Introduction: The use of protease inhibitors, mainly the indinavir, drug recently introduced for the treatment of patients with the human immunodeficiency virus (HIV), has shown formations of crystals and urinary calculi as side effects. Surch conditions are found in 4 percent of patients using indinavir. Case Report: An HIV positive 32 years old male patient taking indinavir and AZT is presented. During treatment, the patient presented left flank pain and left uretero-hydronephrosis at renal ultrasound. Retrograde pyelography showed an image compatible with ureteral calculi. Six month later the patient presented for consultation and an intravenous pyelography and renal ultrasound were normal. Probably, the calculous had passed spontaneously. Conclusions: The benefits of the protease inhibitors for HIV positive patients are enormous and their use are rapidly increasing. Thus, physicians should be aware of this benign complication. Most of these cases are benign and the treatment should be analgesia and oral and parenteral hydration. Patients using indinavir must be advised to maintain adequate hydration