Telmisartán y losartán: las marcadas diferencias entre sus propiedades químicas y farmacológicas pueden explicar la diferencia en la eficacia terapéutica en pacientes hospitalizados con covid-19 / Telmisartan and losartan: marked differences in chemical and pharmacological properties may explain differences in therapeutic efficacy in hospitalized patients with COVID-19

El objetivo de este artículo es comparar las propiedades químicas y farmacológicas del telmisartán y el losartán, y su metabolito activo EXP3174, con el fin de entender por qué el telmisartán es efectivo en pacientes hospitalizados con Covid-19 mientras que el losartán no lo es. Se llevó a cabo una revisión bibliográfica exhaustiva de las propiedades químicas, farmacocinéticas y farmacodinámicas de ambos fármacos y se destacaron las diferencias más importantes que podrían estar relacionadas con su efectividad en pacientes con Covid-19. Se concluyó que las propiedades farmacológicas del telmisartán, como su mayor afinidad por el receptor AT1, su duración de acción prolongada y su capacidad para modular la inflamación podrían explicar su efectividad en pacientes con Covid-19. Por otro lado, las propiedades farmacológicas del losartán, como su menor afinidad por el receptor AT1 y su rápido metabolismo, pueden limitar su efectividad en pacientes con Covid-19. Estos resultados resaltan la importancia de comprender las propiedades químicas y farmacológicas de los medicamentos para identificar posibles candidatos terapéuticos efectivos en el tratamiento de Covid-19. (AU)

The objective of this article is to compare the chemical and pharmacological properties of telmisartan and losartan and their active metabolite EXP3174 to understand why telmisartan is effective in hospitalized patients with COVID-19 while losartan is not. A comprehensive literature review of the chemical, pharmacokinetic and pharmacodynamic properties of both drugs was done to highlight the most important differences that may be related to their efficacy in patients with COVID-19. It was concluded that the pharmacological properties of telmisartan, such as its higher affinity for the AT1 receptor, its long duration of action and its ability to modulate inflammation, could explain its efficacy in patients with COVID-19. On the other hand, the pharmacological properties of losartan, such as its lower affinity for the AT1 receptor and its rapid metabolism, may limit its efficacy in patients with COVID-19. These results highlight the importance of understanding the chemical and pharmacological properties of drugs to identify potential effective therapeutic candidates for the treatment of COVID-19. (AU)

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.

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.

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.

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.

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.

Avaliação dos eixos ECA / ANG II / AT1 e ECA-2 / ANG (1-7) / MAS em fibroblastos de gengiva e ligamento periodontal humanos estimulados por IL-1ß e sua contribuição na produção e regulação de citocinas e quimiocinas / Evaluation ACE /ANG II /AT1 and ACE-2 /ANG (1-7) /MAS axis in gingival and periodontal ligament human fibroblasts stimulated with IL-1ß and its contribution in the production of cytokines and chemokines

O Sistema renina-angiotensina (SRA) tem sido relatado como um importante modulador de processos inflamatórios e imunológicos, incluindo a doença periodontal (DP). Estudos sugerem neste sistema um eixo alternativo (ECA-2 /ANG(1-7) /MAS) que atuaria como um contra-regulador de efeitos mediados pelo clássico eixo (ECA /ANGII /AT1). Sabe-se que bactérias periodontopatogênicas, como a Porphyromonas gingivalis (Pg), possuem componentes bioativos de membrana (ex. lipopolissacarídeos-LPS) capazes de induzir uma forte resposta imune no hospedeiro devido à liberação de citocinas nas células, entre elas Interleucina (IL)- 1ß. Neste contexto, fibroblastos são as células mais abundantes nos tecidos periodontais e possuem em sua superfície celular receptores necessários para o reconhecimento da invasão bacteriana, ativando cascatas intracelulares, que levam à produção de citocinas. O objetivo deste estudo foi verificar se os eixos ECA/ ANGII/ AT1 e ECA-2/ ANG(1-7)/ MAS contribuem para a produção e/ ou regulação de citocinas inflamatórias (CI) por fibroblastos de gengiva humana (HGF) e ligamento periodontal humano (HPLF) estimulados por IL-1ß. Após o pré-tratamento com Losartan e Ang (1-7) ou silenciamento mediado por RNA de interferência (RNAi) de AT1, HGF e HPLF foram estimulados por IL-1ß por 3 horas (RNAm) ou 24 horas (proteína). Expressão de RNAm para AT1, MAS, ECA, ECA-2, IL-1ß, TNF-α, IL-6, IL-8, IL-10, TGF-ß, CXCL12, RANK-L e OPG foram avaliados por RT-qPCR e das proteínas IL-6, IL-8, ECA e ECA-2 por ELISA. Foi realizado também Western Blot para detecção de AT1 e ECA nos extratos celulares e dosagem de nitrito no sobrenadante das culturas. Ambos os subtipos de fibroblastos mostraram aumento da expressão de RNAm para AT1, IL-1ß, IL-6, IL-8, TNF-α e OPG, quando estimulados por IL-1ß. No entanto, apenas em HPLF foi observado aumento para MAS, ECA e TGF-ß. Losartan e Ang (1-7) não modularam o transcrito, a secreção de CI e nem a produção de nitrito no sobrenadante das culturas, tanto em HGF como em HPLF. O silenciamento do receptor AT1 reduziu a secreção de IL-6 e IL-8 induzida por IL-1ß em cultura de HGF e HPLF e aumentou a expressão gênica de OPG somente em HGF. Estes resultados sugerem que o silenciamento de AT1, mas não o bloqueio farmacológico deste receptor pelo antagonista Losartan, em HGF e HPLF, pode controlar a produção de IL-6 e IL-8, que por sua vez contribuem para a patogênese periodontal.(AU)

The renin-angiotensin system (RAS) has been reported as an important modulator of inflammatory and immune responses, including periodontal disease (PD). Studies suggest an alternative axis as part of this system (ACE-2 / ANG (1-7) / MAS) that would act as counter-regulatory to the classical axis (ECA / ANGII / AT1). It is known that periodontal bacteria such as Porphyromonas gingivalis (Pg) have bioactive components in their membrane (such as lipopolysaccharide-LPS) capable of inducing a strong immune response in the host due to the release of cytokines in cells, including interleukin (IL) - 1ß. In this regard, fibroblasts are the most abundant cells in periodontal tissues and receptors needed for the recognition of bacterial invasion by activating intracellular cascades that lead to cytokine production. The aim of this study was to determine whether the axes ACE / ANGII / AT1 and ACE-2 / ANG (1-7) / MAS contribute to the production and / or regulation of inflammatory cytokines (IC) by fibroblasts of human gingiva (HGF) and human periodontal ligament (HPLF) stimulated IL-1ß. After pre-treatment with Losartan, Ang (1-7) or silencing mediated by RNA interference (RNAi) of AT1, HGF and HPLF were stimulated by IL-1ß for 3 hours (RNAm) or 24 hours (protein). Expression mRNA for AT1, MAS, ACE, ACE-2, IL-1ß, TNF-α, IL-6, IL-8, IL-10, TGF-ß, CXCL12, RANK-L and OPG was assessed by RT- qPCR and proteins IL-6, IL-8, ACE and ACE-2 by ELISA. Western Blot for the detection of AT1 and ECA and dosage of nitrite was also performed. Experiments stimulated by IL-1ß showed a positive control for gene expression AT1, IL-1ß, IL-6, IL-8, TNF-α and OPG in HGF and HPLF and MAS, ACE and TGF-ß only HPLF. Losartan and Ang (1-7) did not modulate the transcription and secretion of IC and no nitrite production in the culture supernatant of HGF and HPLF. The silencing AT1 reduced IL-6 secretion and IL-8 induced by IL- ß in cultured HGF and HPLF and increased OPG gene expression only HGF. These results suggest that silencing AT1, but not pharmacological blockade of this receptor by Losartan in HPLF and HGF, can control the production of IL-6 and IL-8, which in turn contribute to the pathogenesis of periodontal disease.(AU)

Olmesartan restores the protective effect of remote ischemic perconditioning against myocardial ischemia/reperfusion injury in spontaneously hypertensive rats

OBJECTIVES: Remote ischemic perconditioning is the newest technique used to lessen ischemia/reperfusion injury. However, its effect in hypertensive animals has not been investigated. This study aimed to examine the effect of remote ischemic perconditioning in spontaneously hypertensive rats and determine whether chronic treatment with Olmesartan could influence the effect of remote ischemic perconditioning. METHODS: Sixty rats were randomly divided into six groups: vehicle-sham, vehicle-ischemia/reperfusion injury, vehicle-remote ischemic perconditioning, olmesartan-sham, olmesartan-ischemia/reperfusion and olmesartan-remote ischemic perconditioning. The left ventricular mass index, creatine kinase concentration, infarct size, arrhythmia scores, HIF-1α mRNA expression, miR-21 expression and miR-210 expression were measured. RESULTS: Olmesartan significantly reduced the left ventricular mass index, decreased the creatine kinase concentration, limited the infarct size and reduced the arrhythmia score. The infarct size, creatine kinase concentration and arrhythmia score during reperfusion were similar for the vehicle-ischemia/reperfusion group and vehicle-remote ischemic perconditioning group. However, these values were significantly decreased in the olmesartan-remote ischemic perconditioning group compared to the olmesartan-ischemia/reperfusion injury group. HIF-1α, miR-21 and miR-210 expression were markedly down-regulated in the Olmesartan-sham group compared to the vehicle-sham group and significantly up-regulated in the olmesartan-remote ischemic perconditioning group compared to the olmesartan-ischemia/reperfusion injury group. CONCLUSION: The results indicate that (1) the protective effect of remote ischemic perconditioning is lost in vehicle-treated rats and that chronic treatment with Olmesartan restores the protective effect of remote ischemic perconditioning; (2) chronic treatment with Olmesartan down-regulates HIF-1α, ...

Bloqueio do receptor AT1 da Angiotensina II reduz o número de folículos antrais em ratas com obesidade induzida por dieta de cafeteria / Blockade of AT1 receptor of Angiotensin II reduces the number of antral follicles in female rats with obesity induced by cafeteria diet

OBJETIVO: Avaliar o desenvolvimento folicular em ratas Wistar com obesidade induzida por dieta de cafeteria (DCAF) submetidas à administração de losartan (LOS), um antagonista do receptor AT1 da Angiotensina II. MÉTODOS: Aos 21 dias de vida, as ratas foram separadas aleatoriamente em dois grupos: controle (CTL), que recebeu ração padrão, e cafeteria (CAF), que recebeu a DCAF, altamente palatável e calórica. Aos 70 dias de vida, início da idade reprodutiva, animais do grupo CAF foram subdivididos em dois grupos (n=15/grupo): CAF, que recebeu água, e CAF+LOS, que recebeu 30 mg/kg de peso corporal (PC) de LOS por gavagem durante 30 dias. O grupo CTL também recebeu água por gavagem. Aos 100 dias de vida foi realizada a eutanásia dos animais e o PC e das gorduras retroperitoneal, perigonadal e subcutânea foi avaliado. Os ovários direitos foram retirados para contagem do número dos diferentes tipos de folículos ovarianos. As concentrações plasmáticas dos hormônios folículo-estimulantes (FSH), luteinizante (LH), prolactina (PRL) e progesterona foram avaliadas. Os resultados foram expressos como média±erro padrão da média. Para análise estatística, foi utilizado one-way ANOVA, seguido pelo pós-teste de Newman-Keuls (p<0,05). RESULTADOS: O PC e das gorduras, assim como o número de folículos antrais, foi elevado no grupo CAF em relação ao CTL. Todavia, as concentrações de FSH e LH foram mais baixas entre os animais CAF. A administração de LOS reduziu o PC e das gorduras retroperitoneal e subcutânea, bem como o número de folículos antrais. O tratamento com LOS atenuou a redução das concentrações de FSH e de LH. As concentrações de progesterona e PRL foram semelhantes entre os grupos estudados. CONCLUSÃO: O uso de LOS pode favorecer o desenvolvimento folicular em fêmeas obesas e pode possibilitar sua utilização como fármaco coadjuvante no tratamento da infertilidade associada à obesidade. .

PURPOSE: To evaluate the follicular development of female Wistar rats with obesity induced by the cafeteria diet, submitted to the administration of losartan (LOS), an antagonist of the AT1 receptor of Angiotensin II. METHODS: At weaning (21 days of age), female Wistar rats were randomly divided, into two groups: control (CTL) that received standard chow and cafeteria (CAF) that received a cafeteria diet, a highly palatable and highly caloric diet. At 70 days of age, at the beginning of the reproductive age, animals of the CAF group were subdivided into two groups (n=15/group): CAF, that received water, and CAF+LOS, that received LOS for 30 days. The CTL group also received water by gavage. At 100 days of age, the animals were euthanized and body weight (BW) as well as the retroperitoneal, perigonadal and subcutaneous fat weights were analyzed. The right ovaries were isolated for counting the number of primary, secondary, antral and mature follicles. Plasma levels of FSH, LH, prolactin and progesterone hormones were analyzed. The results were expressed as mean±standard error of the mean. Data were analyzed statistically by one-way ANOVA followed by the Newman-Keuls post-test (p<0.05). RESULTS: BW and fat weight, as well as the number of antral follicles, were higher in the CAF group compared to the CTL group. However, FSH and LH levels were lower in CAF animals compared to CTL animals. LOS administration attenuated the reduction of FSH and LH levels. Progesterone and PRL levels were similar among groups. CONCLUSION: LOS could improve follicular development in obese females and could be used as an adjunctive drug in the treatment of infertility associated with obesity. .