Endothelial expression of the receptor for advanced glycation end products in experimental diabetes / Expresión endotelial del receptor para productos finales de glicación avanzada en diabetes experimental

The receptor for advanced glycation end products (RAGE) is implicated in the pathogenesis of several chronic diseases including diabetes. The interaction between RAGE and advanced glycation end products (AGEs) promotes gene expression, enhances the release of proinflammatory molecules and causes the generation of oxidative stress in numerous cell types. The aim of this investigation was to evaluate the effect of enalapril and losartan on RAGE expression in abdominal aortic endothelium of rats with experimentally induced diabetes. Male Sprague-Dawley rats, weighing approximately 150 - 200 g, were used. Diabetes was induced in 30 rats by intravenous administration of a single dose of 55 mg/kg body weight of streptozotocin (ETZ). The following groups were studied: control (n=10), diabetic (n=10), losartan-treated diabetic (n=10) and enalapril-treated diabetic (n=10) rats. RAGE expression in aortic endothelium was determined by indirect immunofluorescence. A significant increase in RAGE expression was observed in diabetic animals versus controls (p<0.001), there was a decrease in RAGE expression, in animals treated with losartan versus controls (p<0.01) and in those treated with enalapril (p<0.05) versus control and versus diabetes + vehicle. In conclusion, in the experimental model of ETZ-induced diabetes, there is an increase in RAGE expression at the level of the abdominal aortic endothelium, which can be reversed by treatment with losartan and/or enalapril, two drugs that block the renin-angiotensin system, suggesting its involvement in the molecular events related to vascular damage during diabetes.

El receptor para productos finales de glicación avanzada (RAGE) está implicado en la patogénesis de varias enfermedades crónicas incluyendo la diabetes. La interacción entre RAGE y los productos finales de glicación avanzada (AGEs), promueve la expresión génica, potencia la liberación de moléculas proinflamatorias y provoca la generación de estrés oxidativo en numerosos tipos de células. El objetivo de esta investigación fue evaluar el efecto del enalapril y el losartán sobre la expresión de RAGE en el endotelio de la aorta abdominal de ratas con diabetes inducida experimentalmente. Se utilizaron ratas Sprague-Dawley machos, con un peso aproximado de entre 150 - 200 g. La diabetes se indujo en 30 ratas mediante la administración intravenosa de una sola dosis de 55 mg/Kg de peso corporal de estreptozotocina (ETZ). Se estudiaron los siguientes grupos: ratas control (n=10), diabéticas (n=10), diabéticas tratadas con losartán (n=10) y diabéticas tratadas con enalapril (n=10). La expresión de RAGE en el endotelio aórtico se determinó por inmunofluorescencia indirecta. Se observó un incremento significativo en la expresión de RAGE en los animales diabéticos versus los controles (p<0.001), hubo una disminución en la expresión de RAGE, en los animales tratados con losartán versus los controles (p<0.01) y en los tratados con enalapril (p<0.05) versus control y versus diabetes + vehículo. En conclusión, en el modelo experimental de diabetes inducida por ETZ, existe un incremento en la expresión de RAGE a nivel del endotelio de la aorta abdominal, la cual puede revertirse mediante el tratamiento con losartán y/o enalapril, dos fármacos bloqueadores del sistema renina-angiotensina, lo cual sugiere la participación del mismo en los acontecimientos moleculares relacionados con el daño vascular durante la diabetes.

Bloqueantes de receptores de angiotensina-II de novo para el tratamiento de pacientes con COVID-19 / Angiotensin-II receptor blockers for treating COVID-19 patients

INTRODUCCIÓN: La evidencia actual muestra que la infección por el SARS-CoV-2 progresa en diferentes etapas. Los casos de síndrome de dificultad respiratoria aguda (SDRA) se observan en una proporción significativa de los pacientes frágiles, aproximadamente después de la segunda semana desde la infección, y no se relacionan sólo con la replicación viral no controlada, sino también con la respuesta del huésped.3 El virus SARS-CoV-2 ingresa a las vías respiratorias y se une, por medio de la proteína S en su superficie, a la proteína de membrana de la enzima covertidora de angiotensina 2 (ACE2, Angiotensin-converting enzyme 2) en las células alveolares tipo 2. El complejo proteína S-ACE2 se internaliza por endocitosis y conduce a una disminución parcial o pérdida total de la función enzimática ACE2 en las células alveolares y, a su vez, aumenta la concentración tisular de angiotensina II al disminuir su degradación y reducir la concentración de su antagonista fisiológico, la angiotensina 1-7. Los niveles altos de angiotensina II en el intersticio pulmonar pueden promover la apoptosis iniciando un proceso inflamatorio con liberación de citocinas proinflamatorias, estableciendo una cascada autoamplificada que eventualmente podría conducir al SDRA. Recientemente, Gurwitz y cols propusieron el uso tentativo de novo de agentes como losartán y telmisartán como alternativas para tratar a los pacientes con COVID-19 antes del desarrollo del SDRA. OBJETIVO: El objetivo del presente informe es evaluar parámetros de eficacia, seguridad, conveniencia y recomendaciones disponibles acerca del inicio de novo de los bloqueantes de receptores de angiotensina-II para el tratamiento de pacientes con COVID-19 sin otra indicación para dichos farmacos. MÉTODOS: Se realizó una evaluación de tecnología sanitaria, basada en evidencia proveniente de revisiones sistemáticas vivas y guías de práctica clínica de alta calidad metodológica para brindar parámetros actualizados y balanceados que sean de utilidad para la toma de decisiones en los diferentes niveles de gestión. RESULTADOS: Se identificaron tres revisiones sistemáticas vivas que cumplen con los criterios de inclusión del presente informe y que contienen información actualizada acerca inicio o continuación de bloqueantes de receptores de angiotensina-II para el tratamiento de pacientes con COVID-19. Se identificaron 8 ECAs que incluyeron 1585 pacientes con COVID-19 en los que se comparó inicio o continuación de bloqueantes de receptores de angiotensina-II para el tratamiento de pacientes con COVID-19, con el estándar de cuidado o placebo. CONCLUSIONES: El inicio de tratamiento con bloqueantes de receptores de angiotensina-II para pacientes con COVID-19 podrían no reducir la mortalidad. Existe incertidumbre sobre su efecto en la duración de la hospitalización y sobre el ingreso en la asistencia ventilatoria mecánica, mientras que podrían no aumentar los eventos adversos graves. Los fármacos bloqueantes de los receptores de angiotensina-II se encuentran disponibles en Argentina y aprobados por la Administración Nacional de Medicamentos, Alimentos y Tecnología Médica para el tratamiento de la hipertensión arterial y condiciones asociadas. No se encuentran aprobados por la agencia regulatoria para su uso en ninguno de los estadios de la enfermedad por COVID-19, ni en la prevención de infección en personas expuestas al virus. El costo comparativo es bajo. Las guías de práctica clínica basadas en evidencia recomiendan no utilizar bloqueantes de los receptores de angiotensina-II para el tratamiento de pacientes con COVID-19 que no recibían este tipo de fármacos previamente. El presente informe contempla el empleo de bloqueantes de receptores de angiotensina-II para el tratamiento específico de COVID-19. Sin embargo, de la evidencia analizada podría concluirse que no existen razones para modificar o suspender el tratamiento con bloqueantes de receptores de angiotensina-II en aquellos pacientes que los reciben por otros motivos.

O uso de inibidores do Sistema Renina-Angiotensina pode aumentar a suscetibilidade à infecção pelo SARS-CoV-2 (COVID-19)? / Can the use of Renin-Angiotensin System inhibitors increase the susceptibility to SARSCoV-2 infection (COVID-19)?

Diante do contexto pandêmico da COVID-19, esforços têm sido direcionados ao desenvolvimento de medidas terapêuticas seguras e eficazes no combate à doença. Entretanto, divergências entre as condutas adotadas nesses pacientes tem sido frequentes. Em especial, fármacos inibidores do Sistema Renina-Angiotensina, como os Inibidores da Enzima Conversora de Angiotensina e Bloqueadores do Receptor da Angiotensina, são foco de grande discussão. Diversos autores questionam uma possível relação de risco aumentado entre o uso de tais medicações e o desenvolvimento de formas mais graves da doença, ao correlacionar a regulação positiva da Enzima Conversora de Angiotensina 2 induzida por esses fármacos com o fato do SARS-CoV-2 usar essa enzima como receptor celular. Enquanto isso, outros autores defendem que essa modulação atue como fator protetor à gravidade da infecção, levando em consideração a promoção de efeitos vasodepressores, anti-fibróticos e anti-inflamatórios. Dada a alta prevalência do uso desses anti-hipertensivos, a presente revisão analisa o funcionamento do Sistema Renina-Angiotensina; aspectos moleculares do novo coronavírus; e a inibição da Angiotensina 2 no contexto dessa infecção, para discutir qual conduta seria mais adequada no manejo da hipertensão arterial e doenças cardiovasculares, dada a pandemia da COVID-19.

In the face of the pandemic context of the COVID-19, efforts have been directed to the development of safe and effective therapeutic actions in combating the disease. However, divergences between management of these patients have been frequent. Especially, Renin-Angiotensin System inhibitors, as Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers, are the focus of great discussion. Several authors question a possible increased risk relation between the use of that medication and the development of the most severe disease form, when correlating AngiotensinConverting Enzyme 2 upregulation induced by those drugs with the fact that SARS-CoV-2 uses this enzyme as its cellular receptor. Meanwhile, other authors defend that the referred modulation acts as a protective factor to infection severity, considering the induction of vasodepressor, antifibrotic and anti-inflammatory effects. Given the high prevalence of the use of those antihypertensive drugs, the present review analyses the Renin-Angiotensin System functionning; molecular aspects of the novel coronavirus; and the Angiotensin 2 inhibition in the context of this infection, in order to discuss which conduct would be more appropriate in the management of arterial hypertension and cardiovascular diseases, given the COVID-19 pandemic.

Informe diário de evidências COVID-19: busca realizada em 5 de junho de 2020 / COVID-19 daily evidence report: search conducted on June 5, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referente ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 11 artigos e 7 protocolos.

Informe diário de evidências COVID-19: busca realizada em 9 de junho de 2020 / COVID-19 daily evidence report: search conducted on June 9, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referente ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 14 artigos e 16 protocolos.

Position paper of the department of hypertension of the brazilian society of nephrology: use of renin-angiotensin system blockers during the course of covid-19 infection / Posicionamento do Departamento de Hipertensão da Sociedade Brasileira de Nefrologia: Bloqueadores do sistema renina-angiotensina durante o curso de infecção pela Covid-19

ABSTRACT This position statement of the Department of Hypertension of the Brazilian Society of Nephrology (SBN) addresses the controversy surrounding the use or suspension/replacement of the renin-angiotensin-aldosterone system blockers (particularly inhibitors of the angiotensin-converting enzyme or angiotensin II AT1 receptor blockers) prophylactically in individuals using these drugs, due to the possibility of allegedly worsening the prognosis of hypertensive patients infected with SARS-CoV-2. The SBN Hypertension Department recommends individualizing treatment and maintaining these medications until better scientific evidence is available.

RESUMO Este posicionamento do Departamento de Hipertensão da Sociedade Brasileira de Nefrologia (SBN) trata da polêmica gerada em torno do uso ou da suspensão/substituição dos bloqueadores do sistema renina-angiotensina-aldosterona (particularmente inibidores da enzima de conversão da angiotensina ou bloqueadores dos receptores AT1da angiotensina II) profilaticamente em indivíduos que utilizam esses medicamentos, devido à possibilidade de supostamente piorar o prognóstico de pacientes hipertensos infectados pelo SARS-CoV-2. O Departamento de Hipertensão da SBN recomenda a individualização do tratamento e a manutenção dessas medicações até que melhores evidências científicas estejam disponíveis.

Improved histoarchitectural changes with angiotensin receptor blockers in early testicular and cauda toxicity in rats / Mejora de los cambios en la histoarquitectura con bloqueadores de receptores de angiotensina en la toxicidad precoz testicular y de cauda en ratas

SUMMARY: Reproductive dysfunction is a complication for many diseases and toxins. Its early diagnosis and treatment are immensely important. Here the morphological histoarchitecture changes in early testicular and cauda toxicity before and after treatment with angiotensin receptor blockers were evaluated. Low-grade testicular damage was induced using thioacetamide (TAA, 50 mg/kg/day) intraperitoneally for two weeks in rats. The rats were randomly divided into four groups (n = 8) treated daily orally for three weeks as follows: Normal control (distilled water), TAA (positive control), TAA+candesartan (0.2 mg/kg) and TAA+losartan (7.5 mg/kg). Serum testosterone and testicular malondialdehyde and glutathione were measured. The changes in histoarchitecture of testis and cauda epididymis were evaluated by hematoxylin and eosin for general structure, Masson's trichrome for collagen, periodic acid Schiff for basement membrane, and caspase-3 and proliferating cell nuclear antigen (PCNA) for immunohistochemical analysis. The TAA-rats showed decreases of serum testosterone and testicular glutathione, increases in testicular malondialdehyde, degenerative changes and apoptosis in germ cells, thickening of tubular basal lamina and increases in expression of caspase 3, and decreases in expression of PCNA. The ARBs (candesartan and losartan) significantly reversed these changes with non-significant differences in-between. Treatment with ARBs (candesartan and losartan) significantly reversed TAA-induced low-grade testicular and cauda toxicity in rats. This could be potentially useful for early treatment of male patients with occupational toxicant-induced reproductive dysfunction especially if they are using ARBs for other comorbidities.

RESUMEN: La disfunción reproductiva es una complicación por muchas enfermedades y toxinas. Su diagnóstico y tratamiento tempranos son inmensamente importantes. Aquí se evaluaron los cambios morfológicos en la histoarquitectura en la toxicidad precoz testicular y cauda antes y después del tratamiento con bloqueadores de receptores de angiotensina. Se indujo daño testicular de bajo grado usando tioacetamida (TAA, 50 mg / kg / día) por vía intraperitoneal durante dos semanas en ratas. Las ratas se dividieron aleatoriamente en cuatro grupos (n = 8) tratados diariamente por vía oral durante tres semanas de la siguiente manera: control normal (agua destilada), TAA (control positivo), TAA + candesartan (0,2 mg / kg) y TAA + losartán (7,5 mg / kg). Se midieron la testosterona sérica, el malondialdehído testicular y el glutatión. Los cambios en la histoarquitectura de los testículos y la epidermis de la cauda se evaluaron mediante Hematoxilina y Eosina para determinar la estructura general, con tricrómicro de Masson para el colágeno, ácido periódico de Schiff para la membrana basal y la caspasa-3 y el antígeno nuclear de células proliferantes (PCNA) para análisis inmunohistoquímico. Las ratas TAA mostraron disminución de la testosterona sérica y glutatión testicular, aumentos en el malondialdehído testicular, cambios degenerativos y apoptosis en células germinales, engrosamiento de la lámina basal tubular y aumentos en la expresión de la caspasa 3, y disminución en la expresión de PCNA. Los ARB (candesartán y losartán) revirtieron significativamente estos cambios con diferencias no significativas en el medio. El tratamiento con BRA (candesartán y losartán) revirtió significativamente la toxicidad testicular y cauda inducida por TAA en ratas. Esto podría ser potencialmente útil para el tratamiento temprano de pacientes con disfunción reproductiva inducida por tóxicos ocupacionales, especialmente si están usando BRA para otras comorbilidades.

Effect of telmisartan on expression of metadherin in the kidney of mice with unilateral ureter obstruction / 南方医科大学学报

OBJECTIVE@#To explore the effect of telmisartan on the expression of metadherin in the kidney of mice with unilateral ureter obstruction.@*METHODS@#Eighteen male C57 mice were randomized into sham-operated group, model group and telmisartan treatment group. In the latter two groups, renal interstitial fibrosis as the result of unilateral ureter obstruction (UUO) was induced by unilateral ureteral ligation with or without telmisartan intervention. Renal pathological changes of the mice were assessed using Masson staining, and immunohistochemistry and Western blotting were used to detect the expression of extracellular matrix proteins and metadherin in the kidney of the mice. In the experiment, cultured mouse renal tubular epithelial cells (mTECs) were stimulated with transforming growth factor-β1 (TGF-β1) and transfected with a siRNA targeting metadherin, and the changes in the expressions of extracellular matrix proteins and metadherin were detected using Western blotting.@*RESULTS@#The expressions of extracellular matrix proteins and metadherin increased significantly in the kidney of mice with UUO ( < 0.05). Intervention with telmisartan significantly lowered the expressions of extracellular matrix proteins and metadherin and alleviated the pathology of renal fibrosis in mice with UUO ( < 0.05). In cultured mTECs, siRNA-mediated knockdown of metadherin obviously reversed TGF-β1-induced increase in the expressions of extracellular matrix proteins and metadherin.@*CONCLUSIONS@#Telmisartan can suppress the production of extracellular matrix proteins and the expression of metadhein to attenuate UUO-induced renal fibrosis in mice.

Angiotensin II Type 1 Receptor Blocker, Fimasartan, Reduces Vascular Smooth Muscle Cell Senescence by Inhibiting the CYR61 Signaling Pathway

BACKGROUND AND OBJECTIVES: Angiotensin II (Ang II) has been suggested to accelerate vascular senescence, however the molecular mechanism(s) remain unknown. METHODS: We cultured human coronary artery smooth muscle cells (hCSMCs) and treated Ang II and/or fimasartan. Or we transfected adenoviral vectors expressing CYR61 (Ad-CYR61) or antisense CYR61 (Ad-As-CYR61). Cellular senescence was evaluated senescence-associated β-galactosidase (SA-β-gal) assay. The molecular mechanisms were investigated real-time PCR and western blots. RESULTS: SA-β-gal-positive cells significantly increased in Ang II-treated hCSMCs (5.77±1.43-fold compared with the control). The effect of Ang II was significantly attenuated by pretreatment with the Ang II type 1 receptor blocker, fimasartan (2.00±0.92-fold). The expression of both p53 and p16 senescence regulators was significantly increased by Ang II (p53: 1.39±0.17, p16: 1.19±0.10-fold vs. the control), and inhibited by fimasartan. Cysteine-rich angiogenic protein 61 (CYR61) was rapidly induced by Ang II. Compared with the control, Ad-CYR61-transfected hCSMCs showed significantly increased SA-β-gal-positive cells (3.47±0.65-fold). Upon transfecting Ad-AS-CYR61, Ang II-induced senescence (3.74±0.23-fold) was significantly decreased (1.77±0.60-fold). p53 expression by Ang II was significantly attenuated by Ad-AS-CYR61, whereas p16 expression was not regulated. Ang II activated ERK1/2 and p38 MAPK, which was significantly blocked by fimasartan. ERK and p38 inhibition both regulated Ang II-induced CYR61 expression. However, p53 expression was only regulated by ERK1/2, whereas p16 expression was only attenuated by p38 MAPK. CONCLUSIONS: Ang II induced vascular senescence by the ERK/p38 MAPK–CYR61 pathway and ARB, fimasartan, protected against Ang II-induced vascular senescence.

Actualización en el uso de inhibidores de la neprilisina y del receptor de angiotensina II: onda expansiva en el beneficio sobre distintas entidades / Update on the use of neprilysin inhibitors and angiotensin II receptor: shock wave for the benefit of different entities

Resumen La insuficiencia cardiaca es una de las principales enfermedades a nivel cardiaco debido a su mayor riesgo de mortalidad y de hospitalizaciones por descompensaciones agudas o por presencia de novo de falla cardiaca, por eso en los últimos años se desarrollaron a partir de estudios clínicos randomizados, medicamentos que mejoraran estos eventos, a partir del estudio PARADIGM-HF. Con el surgimiento de sacubitril/valsartan se evaluó su efecto en diferentes escenarios, así el enfoque de este artículo se basa en la revisión de artículos con el objetivo de analizar la importancia de los efectos be neficiosos del sacubitril/valsartan en comparación con enalapril en diferentes análisis y subestudios basado en el estudio PARADIGM-HF, en los cuales se evaluó el impacto del sacubitril/valsartan en diabetes mellitus tipo 2, en la función renal, hipertensión arterial, a nivel de mortalidad y seguridad, a nivel de edad, de hiperkalemia e hiperkalemia severa, en los factores asociados con la falta de cumplimiento durante el período de ejecución antes de la aleatorización y la influen cia en el beneficio estimado de sacubitril/valsartan en el ensayo PARADIGM-HF, eficacia de sacubitril/valsartan con dosis metas bajas, tolerabilidad y seguridad en el inicio de sacubitril/valsartan en insuficiencia cardiaca, efectos de sacubitril/ valsartan asociado a antagonistas de receptores de mineralocorticoides en la reducción de hiperkalemia, implicaciones en el pronóstico de los pacientes con insuficiencia cardiaca con fracción de eyección reducida con los cambios de pépti dos natriuréticos, eficacia y seguridad de sacubitril/valsartan en distintos rangos de edades, efecto del fármaco sobre la terapia de fondo utilizada en insuficiencia cardiaca y eficacia e influencia de sacubitril/valsartan en la fracción de eyección y desenlace primario.

Abstract Descriptores: sacubitril/valsartan, enalapril, insuficiencia cardiaca, péptidos natriureticos Heart failure is one of the main diseases at the cardiac level due to its higher risk of mortality and hospitalizations due to acute decompensation or de novo heart failure, which is why in recent years they were developed from randomized clinical trials. medicines that will improve these events, from there and from the PARADIGM-HF study. From the emergence of sacubitril / valsartan its effect was evaluated in different scenarios, hence the focus of this article was based on the review of articles and with the aim of analyzing the importance of the beneficial effects of sacubitril / valsartan compared to enalapril in different analyzes and substudies from the PARADIGM-HF study, which will evaluate the impact of sacubitril / valsartan in type 2 diabetes mellitus, in renal function, arterial hypertension, in terms of mortality and safety, in terms of age, hyperkalemia and severe hyperkalemia, in the factors associated with non-compliance during the execution period before randomization and the influence on the estimated benefit of sacubitril / valsartan in the PARADIGM-HF trial, efficacy of sacubitril / valsartan with low target doses , tolerability and safety at the onset of sacubitril / valsartan in heart failure, effects of sacubitril / valsartan associated with antag of mineralocorticoid receptors in the reduction of hyperkalemia, implications in the prognosis of patients with heart failure with reduced ejection fraction with changes in natriuretic peptides, efficacy and safety of sacubitril / valsartan in different age ranges, effect of the drug on the background therapy used in heart failure and the efficacy and influence of sacubitril / valsartan on the ejection fraction and primary outcome.

Participation of hepatic α/β-adrenoceptors and AT1 receptors in glucose release and portal hypertensive response induced by adrenaline or angiotensin II

It has been previously demonstrated that the hemodynamic effect induced by angiotensin II (AII) in the liver was completely abolished by losartan while glucose release was partially affected by losartan. Angiotensin II type 1 (AT1) and adrenergic (∝1- and β-) receptors (AR) belong to the G-proteins superfamily, which signaling promote glycogen breakdown and glucose release. Interactive relationship between AR and AT1-R was shown after blockade of these receptors with specific antagonists. The isolated perfused rat liver was used to study hemodynamic and metabolic responses induced by AII and adrenaline (Adr) in the presence of AT1 (losartan) and ∝1-AR and β-AR antagonists (prazosin and propranolol). All antagonists diminished the hemodynamic response induced by Adr. Losartan abolished hemodynamic response induced by AII, and AR antagonists had no effect when used alone. When combined, the antagonists caused a decrease in the hemodynamic response. The metabolic response induced by Adr was mainly mediated by ∝1-AR. A significant decrease in the hemodynamic response induced by Adr caused by losartan confirmed the participation of AT1-R. The metabolic response induced by AII was impaired by propranolol, indicating the participation of β-AR. When both ARs were blocked, the hemodynamic and metabolic responses were impaired in a cumulative effect. These results suggested that both ARs might be responsible for AII effects. This possible cross-talk between β-AR and AT1-R signaling in the hepatocytes has yet to be investigated and should be considered in the design of specific drugs.

Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation / 中国天然药物

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.

Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation / 中国天然药物

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.

Potential radioprotective effect of AT1 receptor antagonists against morphological and ultrastructural changes in the testes induced by ionizing radiation / Potencial efecto radioprotector de antagonistas del receptor AT1 contra los daños morfológicos y ultraestructurales en los testículos inducido por la radiación ionizante

Radiotherapy is a source of human exposure to ionizing radiation. This pure energy causes deleterious effects on tissues, which result from oxidative stress, a phenomenon in which there is the participation of the Renin-Angiotensin System (RAS). The male genital organs are extremely radiosensitive and the action of radiation in the testes can significantly affect spermatogenesis. In search of potential radioprotective for male genital system, this study investigated whether the AT1 receptor antagonists minimize radiation-induced damage to reproductive tissues, by decreasing oxidative stress. Male Wistar rats were divided into six groups: 0 Gray (Gy) (control), 5 Gy (single dose in the scrotal area), telmisartan, losartan, 5Gy+telmisartan and 5Gy+losartan. The treatment started the day after irradiation with losartan 34 mg/kg (two times/day) and telmisartan 12 mg/kg (one time/day) during 60 days. For ultrastructural analysis, the testis fragments were fixed in 2 % glutaraldehyde and 4 % paraformaldehyde in 0.1 M phosphate buffer, pH 7.3. The material was postfixed for 2 h in 1 % osmium tetroxide. For collagen evaluation, the sections were stained with Picrosirius-red method. Serum testosterone was determined. The date showed the deleterious effects of gamma radiation on testicular ultrastructure. Rich accumulation of collagen fibers in the interstitium was observed in the irradiated groups, especially the irradiated and nontreated testes. No significant difference was detected in serum testosterone concentration among the studied experimental groups. Treatments with telmisartan and losartan influenced the onset of attenuation on ultrastructural damages arising from ionizing radiation. Although the data strongly suggest that AT1 receptor antagonists may promote radioprotection to the testes, further studies with a longer duration of treatment are required for these potentially positive effects to be maximized and, therefore, to better characterize radioprotection to reproductive parameters.

El tratamiento radioterápico es una fuente de exposición del ser humano a la radiación ionizante. Esta energía pura causa efectos deletéreos en los tejidos, debido al estrés oxidativo, fenómeno donde hay participación del Sistema Renina-Angiotensina. Los órganos genitales masculinos son extremadamente radiosensibles y la acción de la radiación en los testículos puede afectar significativamente la espermatogénesis. En la búsqueda de potenciales radioprotectores, este estudio ha investigado fármacos antagonistas del receptor AT1 que minimizan los daños radioinduzidos en los tejidos reproductivos, por medio de la disminución del estrés oxidativo. Ratones Wistar machos fueron distribuidos en seis grupos: grupo 0 Gray (Gy) (control), grupo 5 Gy (dosis única en el área escrotal), grupo telmisartán, grupo losartán, grupo 5Gy+telmisartán y grupo 5Gy+losartán. El tratamiento empezó en el día siguiente a la irradiación con losartán 34 mg/kg (2x/día) y telmisartán 12 mg/kg (1x/día), durante 60 días. Para el análisis ultraestructural, los testículos se fijaron en glutaraldehido (2 %) y paraformaldehido (4 %) con tampón de fosfato 0,1 M, pH 7,3. El material fue post-fijado en tetróxido de osmio (1 %). Para evaluar el colágeno fue utilizado el método Picrosirius Red. Fue determinada la concentración sérica de testosterona. Los datos mostraron los efectos deletéreos de los rayos gamma sobre la ultraestructura testicular. Fue observada una rica deposición de colágeno en el intersticio en los grupos irradiados, especialmente en el irradiado y no tratado. Entre los grupos, no se detectó ninguna diferencia significativa en la concentración sérica de testosterona. Los tratamientos con telmisartán y losartán influenciaron el comienzo de la atenuación de los cambios en la ultraestructura testicular de la radiación. A pesar de que los datos sugieren que los antagonistas del receptor AT1 pueden promover radioprotección a los testículos, estudios complementarios con una duración de tratamiento más extendida son necesarios para que los efectos potencialmente positivos sean maximizados y, por supuesto, puedan mejorar la caracterizacion de la radioprotección a los parámetros reproductivos.

Farmácia Popular Program: pharmaceutical market analysis of antihypertensive acting on the renin-angiotensin system medicines / Programa Farmácia Popular: análise do mercado farmacêutico de anti-hipertensivos do sistema renina-angiotensina

Abstract This paper aims to analyse changes in the retail pharmaceutical market following policy changes in the Farmácia Popular Program (FP), a medicines subsidy program in Brazil. The retrospective longitudinal analyses focus on therapeutic class of agents acting on the renin-angiotensin system. Data obtained from QuintilesIMS (formerly IMS Health) included private retail pharmacy sales volume (pharmaceutical units) and sales values from 2002 to 2013. Analyses evaluated changes in market share following key FP policy changes. The therapeutic class was selected due to its relevance to hypertension treatment. Market share was analysed by therapeutic sub-classes and by individual company. Losartan as a single product accounted for the highest market share among angiotensin II antagonists. National companies had higher sales volume during the study period, while multinational companies had higher sales value. Changes in pharmaceutical market share coincided with the inclusion of specific products in the list of medicines covered by FP and with increases in or exemption from patient copayment.

Resumo Este artigo visa analisar as mudanças no mercado de varejo farmacêutico, seguindo as alterações de diretiva no Programa Farmácia Popular (FP), que realiza subvenção de medicamentos no Brasil, em parceria pública privada. Foi realizada análise longitudinal retrospectiva dos medicamentos da classe terapêutica dos agentes que atuam sobre o sistema renina-angiotensina. Os dados obtidos do QuintilesIMS incluíram o varejo farmacêutico em termos do volume e valores de vendas de 2002 a 2013. Análises realizadas consideraram intervenções e reformas ocorridas no FP e seu impacto no mercado farmacêutico da classe terapêutica selecionada, devido a sua relevância para o tratamento da hipertensão. Também se examinou o comportamento do mercado tomando por base as empresas farmacêuticas produtoras. Losartan monodroga representou a maior fatia de mercado entre os antagonistas de angiotensina II. Empresas nacionais obtiveram maior volume de vendas durante o período de estudo, enquanto as empresas multinacionais exibiram maior valor de vendas. Mudanças no mercado farmacêutico coincidiram com a inclusão de produtos específicos na lista de medicamentos abrangidos pelo FP e com aumentos ou isenção de copagamento pelos pacientes.

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.

Influence of antihypertensive drugs on aortic and coronary effects of Ang-(1-7) in pressure-overloaded rats

This study investigated the influence of antihypertensive drugs, such as angiotensin-converting enzyme inhibitors (ACEIs), AT1 receptor blockers (ARBs), voltage-gated L-type calcium channel blockers, and mineralocorticoid receptor antagonists (MRAs), on the effects of angiotensin-(1-7) [Ang-(1-7)] on aorta and coronary arteries from pressure-overloaded rats. Pressure overload was induced by abdominal aortic banding (AB). To evaluate the role of antihypertensive drugs on the effect of Ang-(1-7), AB male Wistar rats weighing 250–300 g were treated with vehicle or low doses (5 mg·kg-1·day-1, gavage) of losartan, captopril, amlodipine, or spironolactone. Isolated aortic rings and isolated perfused hearts under constant flow were used to evaluate the effect of Ang-(1-7) in thoracic aorta and coronary arteries, respectively. Ang-(1-7) induced a significant relaxation in the aorta of sham animals, but this effect was reduced in the aortas of AB rats. Chronic treatments with losartan, captopril or amlodipine, but not with spironolactone, restored the Ang-(1-7)-induced aorta relaxation in AB rats. The coronary vasodilatation evoked by Ang-(1-7) in sham rats was blunted in hypertrophic rats. Only the treatment with losartan restored the coronary vasodilatory effect of Ang-(1-7) in AB rat hearts. These data support a beneficial vascular effect of an association of Ang-(1-7) and some antihypertensive drugs. Thus, this association may have potential as a new therapeutic strategy for cardiovascular diseases.

Candesartan, rather than losartan, improves motor dysfunction in thioacetamide-induced chronic liver failure in rats

Minimal hepatic encephalopathy is more common than the acute syndrome. Losartan, the first angiotensin-II receptor blocker (ARB), and candesartan, another widely-used ARB, have protected against developing fibrogenesis, but there is no clear data about their curative antifibrotic effects. The current study was designed to examine their effects in an already-established model of hepatic fibrosis and also their effects on the associated motor dysfunction. Low-grade chronic liver failure (CLF) was induced in 3-month old Sprague-Dawley male rats using thioacetamide (TAA, 50 mg·kg−1·day−1) intraperitoneally for 2 weeks. The TAA-CLF rats were randomly divided into five groups (n=8) treated orally for 14 days (mg·kg−1·day−1) as follows: TAA (distilled water), losartan (5 and 10 mg/kg), and candesartan (0.1 and 0.3 mg/kg). Rats were tested for rotarod and open-field tests. Serum and hepatic biochemical markers, and hepatic histopathological changes were evaluated by H&E and Masson's staining. The TAA-CLF rats showed significant increases of hepatic malondialdehyde, hepatic expression of tumor necrosis factor-α (TNF-α), and serum ammonia, alanine aminotransferase, γ-glutamyl transferase, TNF-α, and malondialdehyde levels as well as significant decreases of hepatic and serum glutathione levels. All treatments significantly reversed these changes. The histopathological changes were moderate in losartan-5 and candesartan-0.1 groups and mild in losartan-10 and candesartan-0.3 groups. Only candesartan significantly improved TAA-induced motor dysfunction. In conclusion, therapeutic antifibrotic effects of losartan and candesartan in thioacetamide-induced hepatic fibrosis in rats are possibly through angiotensin-II receptor blocking, antioxidant, and anti-inflammatory activities. Improved motor dysfunction by candesartan could be attributed to better brain penetration and slower "off-rate" from angiotensin-II receptors. Clinical trials are recommended.