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1.
J Cardiovasc Pharmacol ; 65(1): 8-12, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25165996

RESUMEN

Plasma angiotensin-converting enzyme (ACE) 2 activity has been demonstrated to be an independent prognostic marker in Chagas' disease, equally potent as B-type natriuretic peptide. This study aimed to investigate the prognostic potency of circulating ACE2 activity in patients with idiopathic dilated cardiomyopathy (DCM). Blood samples were withdrawn from patients with idiopathic DCM and healthy control subjects. The DCM patients were subdivided into 2 groups according to their New York Heart Association classification. The plasma ACE2 activity was measured by a fluorescence method. Plasma ACE2 activity was significantly increased in DCM patients, correlating with clinical severity. It was correlating with echocardiographic parameters in patients with DCM. Furthermore, plasma ACE2 activity had the potency to predict cardiac death and heart transplantation. However, compared with patients with Chagas' disease, the correlation and predictive value of ACE2 activity in patients with DCM was much less pronounced. Beta blocker treatment in patients with DCM was identified to prevent the association between circulating ACE2 activity and echocardiographic parameters. Although ACE2 activity in blood samples of patients with DCM without beta blockers is potent in correlating with the severity of disease and in predicting death and heart transplantation, its correlation and prediction potency are significantly diminished by beta blocker treatment.


Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Cardiomiopatía Dilatada/tratamiento farmacológico , Peptidil-Dipeptidasa A/sangre , Antagonistas Adrenérgicos beta/farmacología , Adulto , Enzima Convertidora de Angiotensina 2 , Cardiomiopatía Dilatada/fisiopatología , Estudios de Casos y Controles , Muerte , Ecocardiografía , Femenino , Trasplante de Corazón/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Índice de Severidad de la Enfermedad
2.
Cytokine ; 61(3): 728-31, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23357302

RESUMEN

Chagas' disease (CD) often leads to dilated cardiomyopathy (DCM), and during its chronic stage hematopoietic stem or progenitor cells are involved in its pathological process. However, it is not clear whether stem cell growth factor (SCGF) beta can be regulated in patients with CD and idiopathic DCM. In present study, we aim to investigate the plasma SCGF beta concentration and its correlation with echocardiographic parameters and clinical outcome. In this prospective cohort study, SCGF beta levels were quantified in patients with CD (n=94), DCM (n=48), and control healthy subjects (n=25). In comparison with healthy subjects, no statistical difference can be detected in NYHA classes I-II patients. However, SCGF beta was significantly increased in advanced heart failure patients (NYHA III-IV), compared to CD patients without heart failure. There was no group difference between CD and DCM. However, despite this significant increase in advanced heart failure patients, SCGF beta had no significant correlation with echocardiographic parameters, and it cannot be used as a prognostic marker for mortality and heart transplantation. To our best knowledge, this is the first report of SCGF beta in heart failure patients. Although it is significantly increased in advanced heart failure patients caused by CD or DCM, its prognostic value for end points is minor.


Asunto(s)
Cardiomiopatía Dilatada/sangre , Enfermedad de Chagas/sangre , Factores de Crecimiento de Célula Hematopoyética/sangre , Lectinas Tipo C/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico
3.
Cardiology ; 121(4): 240-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22555361

RESUMEN

OBJECTIVES: Hepatocyte growth factor (HGF) plays an important role in the improvement in cardiac function and remodeling in a variety of cardiovascular diseases. It is also a strong predictor of mortality in some heart failure (HF) patients. However, its prognostic value in patients with Chagas' disease (CD) or idiopathic dilated cardiomyopathy (DCM) remains to be investigated. METHODS AND RESULTS: In this prospective cohort study, HGF concentrations were measured in patients with CD (n = 91), DCM (n = 47), and control subjects (n = 25). While no difference was detected for patients with New York Heart Association class I-II, HGF was significantly increased in advanced HF patients (New York Heart Association class III-IV) in both CD and DCM groups, compared with healthy subjects. There was a strong correlation between HGF and left ventricular ejection fraction in CD patients. However, there was no correlation in patients with DCM. Despite its strong correlation with left ventricular ejection fraction in CD patients, HGF failed to predict mortality and necessity for heart transplant in both CD and DCM patients. CONCLUSIONS: Although HGF can be significantly increased in advanced HF patients with CD and DCM, its prognostic value for endpoints is minor. Therefore, the formerly described predictive power for HGF in HF might be restricted to specific etiologies of HF.


Asunto(s)
Biomarcadores/sangre , Cardiomiopatía Dilatada/sangre , Enfermedad de Chagas/sangre , Factor de Crecimiento de Hepatocito/sangre , Presión Sanguínea/fisiología , Cardiomiopatía Dilatada/mortalidad , Enfermedad de Chagas/mortalidad , Femenino , Insuficiencia Cardíaca/diagnóstico , Trasplante de Corazón , Humanos , Masculino , Pronóstico , Tasa de Supervivencia
4.
J Cardiovasc Pharmacol ; 58(4): 374-9, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21697726

RESUMEN

Chagas disease (CD), which is caused by the protozoan Trypanosoma cruzi, is a major cause of heart failure in Latin America. We investigated if plasma activity of one of the enzymes being part of the renin-angiotensin system, aminopeptidase A (APA), has diagnostic and prognostic potency in patients with CD and dilated cardiomyopathies (DCMs) due to other causes. Blood samples were taken from 94 patients with CD, 46 patients with DCM, and 34 healthy control subjects. Plasma APA activity was determined by fluorometry assays. The average follow-up time was 39 months; by the end of study, 33 patients had died and another 13 received heart transplant. There was no significant alteration in plasma APA activity in the patients with CD or DCM, as compared with that in controls. The Pearson correlation of echocardiographic data with plasma APA activity in patients with CD and DCM did not reveal any significant correlation with left-ventricular ejection fraction or other echocardiographic parameters. APA activity was unable to predict mortality or the need for heart transplant. Detection of APA activity in plasma may not prove suitable for prognosis in patients with heart failure and is unable to screen or diagnose asymptomatic patients with CD for early therapy.


Asunto(s)
Cardiomiopatía Dilatada/fisiopatología , Enfermedad de Chagas/fisiopatología , Glutamil Aminopeptidasa/sangre , Adulto , Cardiomiopatía Dilatada/diagnóstico , Estudios de Casos y Controles , Enfermedad de Chagas/diagnóstico , Estudios de Cohortes , Ecocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Función Ventricular Izquierda
5.
J Card Fail ; 16(2): 157-63, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20142028

RESUMEN

BACKGROUND: Angiotensin-converting enzyme (ACE) 2 is a novel homologue of ACE. It metabolizes angiotensin (Ang)II to Ang-(1-7). This study aims to investigate the diagnostic and prognostic potency of circulating ACE2 activity in patients with heart failure (HF) from Chagas' disease (CD). METHODS AND RESULTS: Blood samples were obtained from 111 CD patients and 40 age- and gender-matched healthy subjects. The CD patients were further subdivided according to their New York Heart Association classification. ACE2 activity was significantly increased in CD patients with HF, but not in patients without systolic dysfunction. Moreover, plasma ACE2 activity was significantly correlated with their clinical severity and echocardiographic parameters. Importantly, the potency of circulating ACE2 activity in CD patients was equally potent as that of B-type natriuretic peptide to predict cardiac death and heart transplant. Most importantly, patients with both parameters elevated were on a 5-fold higher risk to reach an endpoint than patients with increase in only 1 of the 2 parameters. CONCLUSIONS: Determination of ACE2 activity may provide a new and important diagnostic and prognostic marker for patients with CD. ACE2 activity and BNP concentration have additive predictive value and may be used in combination to offer a new dimension of prediction in HF.


Asunto(s)
Enfermedad de Chagas/sangre , Enfermedad de Chagas/diagnóstico , Péptido Natriurético Encefálico/sangre , Peptidil-Dipeptidasa A/sangre , Enzima Convertidora de Angiotensina 2 , Biomarcadores/sangre , Enfermedad de Chagas/enzimología , Enfermedad de Chagas/mortalidad , Estudios de Cohortes , Activación Enzimática/fisiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos
6.
J Cardiovasc Pharmacol ; 55(1): 62-6, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20090473

RESUMEN

Atrial and B-type natriuretic peptides (ANP and BNP), but not C-type natriuretic peptide (CNP), have been identified to be diagnostic and prognostic markers in Chagas disease (CD). Although ANP and BNP excessively rise in patients with CD, increase in CNP is just minor. Our study aimed to investigate the mechanisms leading to CNP insensitivity to heart failure (HF) stimuli. Amino-terminal fragment of CNP precursor (NT-proCNP) and activity of neutral endopeptidase (NEP) were quantified to monitor CNP generation and degradation, respectively. Blood samples were collected from patients with CD and control healthy subjects. NT-proCNP concentrations were significantly lower in patients with CD without systolic dysfunction compared with healthy subjects. Despite a trend toward increase with rising heart failure clinical severity, it was significantly correlated with left ventricular ejection fraction and other echocardiographic parameters. As shown for CNP before, NT-proCNP could not predict mortality and heart transplant. Importantly, it had no statistical correlation with CNP. Additionally, NEP activity was significantly increased in New York Heart Association III and IV patients with HF but was positively correlated with CNP concentration. Our data demonstrates that generation of CNP is not enhanced under HF condition like CD. Thus, CNP rise by severe HF is caused by its less degradation that is independent of NEP activity.


Asunto(s)
Enfermedad de Chagas/fisiopatología , Insuficiencia Cardíaca/etiología , Péptido Natriurético Tipo-C/metabolismo , Estudios de Casos y Controles , Enfermedad de Chagas/complicaciones , Enfermedad de Chagas/mortalidad , Estudios de Cohortes , Femenino , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Neprilisina/metabolismo , Pronóstico , Estudios Prospectivos , Índice de Severidad de la Enfermedad
7.
Genomics ; 94(3): 188-95, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19501643

RESUMEN

Intellectual disability (ID) is a common developmental disability observed in 1 to 3% of the human population. A possible role for the Angiotensin II type 2 receptor (AGTR2) in brain function, affecting learning, memory, and behavior, has been suggested in humans and rodents. Mice lacking the Agtr2 gene (Agtr2(-/y)) showed significant impairment in their spatial memory and exhibited abnormal dendritic spine morphology. To identify Agtr2 influenced genes and pathways, we performed whole genome microarray analysis on RNA isolated from brains of Agtr2(-/y) and control male mice at embryonic day 15 (E15) and postnatal day one (P1). The gene expression profiles of the Agtr2(-/y) brain samples were significantly different when compared to profiles of the age-matched control brains. We identified 62 differently expressed genes (p< or =0.005) at E15 and in P1 brains of the Agtr2(-/y) mice. We verified the differential expression of several of these genes in brain samples using quantitative RT-PCR. Differentially expressed genes encode molecules involved in multiple cellular processes including microtubule functions associated with dendritic spine morphology. This study provides insight into Agtr2 influenced candidate genes and suggests that expression dysregulation of these genes may modulate Agtr2 actions in the brain that influences learning and memory.


Asunto(s)
Biomarcadores/metabolismo , Encéfalo/metabolismo , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Receptor de Angiotensina Tipo 2/fisiología , Transducción de Señal , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
Haematologica ; 94(6): 857-60, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19377080

RESUMEN

Effects of angiotensin (Ang)-(1-7), an AngII metabolite, on bone marrow-derived hematopoietic cells were studied. We identified Ang-(1-7) to stimulate proliferation of human CD34(+) and mononuclear cells in vitro. Under in vivo conditions, we monitored proliferation and differentiation of human cord blood mononuclear cells in NOD/SCID mice. Ang-(1-7) stimulated differentially human cells in bone marrow and accumulated them in the spleen. The number of HLA-I(+) and CD34(+) cells in the bone marrow was increased 42-fold and 600-fold, respectively. These results indicate a decisive impact of Ang-(1-7) on hematopoiesis and its promising therapeutic potential in diseases requiring progenitor stimulation.


Asunto(s)
Angiotensina I/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Angiotensina I/administración & dosificación , Animales , Antígenos CD19/análisis , Antígenos CD34/análisis , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Antígeno CD11a/análisis , Células Cultivadas , Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Relación Dosis-Respuesta a Droga , Sangre Fetal/citología , Sangre Fetal/metabolismo , Citometría de Flujo , Antígenos HLA-DR/análisis , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Humanos , Inyecciones Subcutáneas , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/metabolismo , Antígeno Lewis X/análisis , Ratones , Ratones Endogámicos NOD , Ratones SCID , Fragmentos de Péptidos/administración & dosificación , Bazo/citología , Bazo/efectos de los fármacos , Bazo/metabolismo , Factores de Tiempo , Trasplante Heterólogo
9.
FASEB J ; 22(8): 3068-77, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18497303

RESUMEN

Angiotensin II activates two distinct receptors, the angiotensin II receptors type 1 (AT(1)) and type 2 (AT(2)). In rodents, two AT(1) subtypes were identified (AT(1a) and AT(1b)). To determine receptor-specific functions and possible angiotensin II effects independent of its three known receptors we generated mice deficient in either one of the angiotensin II receptors, in two, or in all three (triple knockouts). Triple knockouts were vital and fertile, but survival was impaired. Hypotension and renal histological abnormalities in triple knockouts were comparable to those in mice lacking both AT(1) subtypes. All combinations lacking AT(1a) were distinguished by reduced heart rate. AT(1a) deletion impaired the in vivo pressor response to angiotensin II bolus injection, whereas deficiency for AT(1b) and/or AT(2) had no effect. However, the additional lack of AT(1b) in AT(1a)-deficient mice further impaired the vasoconstrictive capacity of angiotensin II. Although general vasoconstrictor properties were not changed, angiotensin II failed to alter blood pressure in triple knockouts, indicating that there are no other receptors involved in direct angiotensin II pressor effects. Our data identify mice deficient in all three angiotensin II receptors as an ideal tool to better understand the structure and function of the renin-angiotensin system and to search for angiotensin II effects independent of AT(1) and AT(2).


Asunto(s)
Presión Sanguínea/fisiología , Receptor de Angiotensina Tipo 2/deficiencia , Angiotensina II/administración & dosificación , Angiotensina II/sangre , Animales , Secuencia de Bases , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/genética , Cartilla de ADN/genética , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/genética , Frecuencia Cardíaca/fisiología , Riñón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Receptor de Angiotensina Tipo 1/deficiencia , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 1/fisiología , Receptor de Angiotensina Tipo 2/clasificación , Receptor de Angiotensina Tipo 2/genética , Receptor de Angiotensina Tipo 2/fisiología , Sistema Renina-Angiotensina/genética , Sistema Renina-Angiotensina/fisiología , Vasoconstricción/genética , Vasoconstricción/fisiología
10.
Circulation ; 115(3): 333-44, 2007 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-17210842

RESUMEN

BACKGROUND: Strong evidence suggests that mitochondrial malfunction, which leads to disturbed energy metabolism and stimulated apoptosis, is a linchpin in the induction and manifestation of cardiac failure. An adequate exchange of ATP and ADP over the inner mitochondrial membrane by the adenine nucleotide translocase (ANT) is thereby essential to guarantee the cellular energy supply. METHODS AND RESULTS: To explore the effect of an ameliorated mitochondrial ATP/ADP transportation on cardiac dysfunction, we generated transgenic rats overexpressing ANT1 in the heart (ANT rats) and crossed them with renin-overexpressing rats (REN rats) suffering from hypertension-induced cardiac insufficiency. Cardiac-specific ANT1 overexpression resulted in a higher ATP/ADP transportation and elevated activities of respiratory chain complexes. Increased ANT activity in double-transgenic (ANT/REN) animals did not influence excessive hypertension seen in REN rats. Hypertension-induced cardiac hypertrophy in the REN rats was prevented by parallel ANT1 overexpression, however, and left ventricular function remarkably improved. The ANT1 overexpression led to a reduction in fibrosis and an improvement in cardiac tissue architecture. Consequently, the survival rate of ANT/REN rats was enhanced. Further investigations into the cardioprotective mechanism of ANT1 overexpression revealed improved mitochondrial structure and function and significantly reduced apoptosis in ANT/REN rats, shown by lowered cytosolic/mitochondrial cytochrome c ratio, reduced caspase 3 level, and prevented DNA degradation. CONCLUSIONS: Myocardial ANT1 overexpression protects against hypertension-induced cardiac pathology. Thus, the improvement in mitochondrial function may be a basic principle for new strategies in treating heart disease.


Asunto(s)
Translocador 1 del Nucleótido Adenina/metabolismo , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/metabolismo , Cardiopatías/prevención & control , Hipertensión/complicaciones , Mitocondrias Cardíacas/metabolismo , Translocasas Mitocondriales de ADP y ATP/metabolismo , Translocador 1 del Nucleótido Adenina/genética , Animales , Animales Modificados Genéticamente , Apoptosis , Transporte Biológico/fisiología , Caspasa 3/metabolismo , Citocromos c/metabolismo , Daño del ADN , Regulación de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Cardiopatías/etiología , Cardiopatías/patología , Cardiopatías/fisiopatología , Hipertensión/fisiopatología , Translocasas Mitocondriales de ADP y ATP/genética , Ratas , Ratas Sprague-Dawley , Renina/genética , Renina/metabolismo , Tasa de Supervivencia
11.
Eur J Pharmacol ; 590(1-3): 276-80, 2008 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-18571157

RESUMEN

Angiotensin-(1-7) is associated with beneficial effects in cardiovascular diseases. In this study, we determined the effect of AVE0991, a nonpeptide angiotensin-(1-7) receptor agonist, on cardiac function in an animal model of diabetes mellitus type I. Diabetes was induced in Sprague-Dawley rats by a single injection of streptozotocin (70 mg/kg). Diabetic and non-diabetic animals were fed with AVE0991 (20 mg/kg per day) or control chow. Normoglycemic control chow- or AVE0991-fed rats served as controls (n=10/group). After five weeks, metabolic cage experiments were performed to assess metabolic parameters. Six weeks after induction of diabetes, cardiac function was monitored using a Millar-tip catheter system. AVE0991 had no effect on any of the investigated hemodynamic parameters under normoglycemic conditions. Hyperglycemia was comparable in diabetic animals with or without AVE0991 treatment. Diabetic control rats suffered from severe systolic dysfunction, indicated by a significant decrease in heart rate, left ventricular systolic pressure, systolic blood pressure and an impairment of left ventricular contractility. Administration of AVE0991 clearly rescued cardiac function under diabetic conditions as indicated by a normalisation of blood pressure and contractility parameters. Our data demonstrates a dominant beneficial impact of AVE0991 on the diabetic heart, implying a cardioprotective role for angiotensin-(1-7) under hyperglycemic conditions and thus pointing to new therapeutic strategies using angiotensin-(1-7) agonists to treat cardiovascular complications in diabetes mellitus.


Asunto(s)
Diabetes Mellitus Experimental/fisiopatología , Corazón/efectos de los fármacos , Imidazoles/farmacología , Proteínas Proto-Oncogénicas/agonistas , Receptores Acoplados a Proteínas G/agonistas , Animales , Presión Sanguínea/efectos de los fármacos , Corazón/fisiopatología , Masculino , Óxido Nítrico/biosíntesis , Proto-Oncogenes Mas , Ratas , Ratas Sprague-Dawley , Estreptozocina , Función Ventricular Izquierda/efectos de los fármacos
12.
Cardiology ; 110(4): 217-25, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18073475

RESUMEN

BACKGROUND: Chagas' disease (CD) affects around 18 million people in Latin America. To determine the diagnostic and prognostic value of natriuretic peptides in patients with CD, we measured atrial (ANP) and brain natriuretic peptide (BNP), and compared the findings with other dilated cardiomyopathies (DCM). METHODS: Blood samples were obtained from 111 CD patients, 62 patients with DCM due to other causes, and 43 gender- and age-matched healthy subjects. The CD and DCM patients were subdivided according to their NYHA classification. Natriuretic peptide concentrations were determined by immunoradiometric assays. RESULTS: ANP and more pronounced BNP levels were increased in CD and DCM patients in relation to the NYHA class. Circulating BNP concentrations were higher in CD patients in NYHA classes I-II than in the corresponding DCM patients (p = 0.020). Importantly, ANP and BNP were already significantly elevated in CD patients without systolic ventricular dysfunction (p < or = 0.001). In CD patients, both peptides were highly correlated with echocardiographic parameters (p < 10(-14)). Both ANP and BNP had comparable ability to predict death or the necessity for heart transplant (p < 0.0001). CONCLUSION: Natriuretic peptide levels can be used as a marker of asymptomatic CD without ventricular dysfunction and thus could be an ideal tool to identify these patients for early therapy.


Asunto(s)
Factor Natriurético Atrial/sangre , Enfermedad de Chagas/sangre , Péptido Natriurético Encefálico/sangre , Adulto , Biomarcadores/sangre , Presión Sanguínea , Estudios de Casos y Controles , Enfermedad de Chagas/mortalidad , Enfermedad de Chagas/fisiopatología , Enfermedad de Chagas/cirugía , Ecocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Trasplante de Corazón/estadística & datos numéricos , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Curva ROC , Volumen Sistólico
13.
J Hypertens ; 25(12): 2421-5, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17984663

RESUMEN

BACKGROUND: Endothelial dysfunction is an initial step in the pathogenesis of cardiovascular diseases. Since we previously identified the G protein-coupled receptor Mas as a receptor for angiotensin (Ang)-(1-7), a heptapeptide with endothelium-dependent vasorelaxant properties, we investigated whether alterations on the Ang-(1-7)/Mas axis alter endothelial function. RESULTS: Ang-(1-7)-mediated relaxation of murine wild-type mesenteric arteries was equally impaired in both wild-type arteries pretreated with the Ang-(1-7) receptor blocker, A779, and arteries isolated from Mas-deficient mice. Importantly, the response to the endothelium-dependent vasorelaxant, bradykinin (BK), and acetylcholine (ACh) effects were comparably inhibited, while endothelium-independent vessel relaxation by sodium nitroprusside was unaltered in these vessels. Hypothesizing endothelial dysfunction, we proved the in-vivo relevance of the ex-vivo findings investigating mesenteric properties after 1 week of minipump infusion of A779 in wild-type mice. Both BK- and ACh-induced relaxation were significantly impaired in wild-type vessels of pretreated animals. A779-induced impairment of endothelial function was confirmed in vitro, since BK-mediated nitric oxide (NO) release was increased by Ang-(1-7) and blunted by A779 pretreatment in primary human endothelial cell cultures. CONCLUSIONS: Our data highlight a pivotal role for the receptor Mas in preserving normal vascular relaxation. Consequently, Mas agonists arise as a promising tool in the treatment of cardiovascular diseases characterized by endothelial dysfunction.


Asunto(s)
Endotelio Vascular/fisiopatología , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Acetilcolina/farmacología , Angiotensina I/farmacología , Angiotensina II/análogos & derivados , Angiotensina II/farmacología , Animales , Bradiquinina/farmacología , Células Cultivadas , Endotelio Vascular/efectos de los fármacos , Humanos , Técnicas In Vitro , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/fisiología , Fragmentos de Péptidos/farmacología , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas/agonistas , Proteínas Proto-Oncogénicas/deficiencia , Proteínas Proto-Oncogénicas/fisiología , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/deficiencia , Receptores Acoplados a Proteínas G/fisiología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiología
14.
Circulation ; 111(14): 1806-13, 2005 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-15809376

RESUMEN

BACKGROUND: We previously identified the G-protein-coupled receptor Mas, encoded by the Mas proto-oncogene, as an endogenous receptor for the heptapeptide angiotensin-(1-7); however, the receptor is also suggested to be involved in actions of angiotensin II. We therefore tested whether this could be mediated indirectly through an interaction with the angiotensin II type 1 receptor, AT1. METHODS AND RESULTS: In transfected mammalian cells, Mas was not activated by angiotensin II; however, AT1 receptor-mediated, angiotensin II-induced production of inositol phosphates and mobilization of intracellular Ca2+ was diminished by 50% after coexpression of Mas, despite a concomitant increase in angiotensin II binding capacity. Mas and the AT1 receptor formed a constitutive hetero-oligomeric complex that was unaffected by the presence of agonists or antagonists of the 2 receptors. In vivo, Mas acts as an antagonist of the AT1 receptor; mice lacking the Mas gene show enhanced angiotensin II-mediated vasoconstriction in mesenteric microvessels. CONCLUSIONS: These results demonstrate that Mas can hetero-oligomerize with the AT1 receptor and by so doing inhibit the actions of angiotensin II. This is a novel demonstration that a G-protein-coupled receptor acts as a physiological antagonist of a previously characterized receptor. Consequently, the AT1-Mas complex could be of great importance as a target for pharmacological intervention in cardiovascular diseases.


Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/fisiología , Receptores Acoplados a Proteínas G/fisiología , Angiotensina II/antagonistas & inhibidores , Angiotensina II/farmacología , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Animales , Células CHO , Calcio/metabolismo , Cricetinae , Técnicas In Vitro , Fosfatos de Inositol/metabolismo , Arterias Mesentéricas/efectos de los fármacos , Ratones , Ratones Noqueados , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas/genética , Transfección , Vasoconstricción/efectos de los fármacos
15.
Regul Pept ; 116(1-3): 95-100, 2003 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-14599720

RESUMEN

BACKGROUND: Since first reports demonstrated interactions between the natriuretic peptide (NPS) and renin-angiotensin system (RAS), our experiments should clarify whether cardiac brain natriuretic peptide (BNP) is regulated in mice genetically altered for components of the RAS. METHODS AND RESULTS: The study was carried out in hypotensive AT1- and angiotensinogen (ANG)-, and normotensive AT2-knockout mice, and in hypertensive animals overexpressing ANG and wildtype controls of each genotype. Ventricular BNP expression was analyzed by RNase-protection assay (RPA) (n=6). Cardiac fibrosis was visualized by Sirius red staining. While ANG overexpression increases cardiac BNP-mRNA expression (1035+/-210 vs. wildtype: 405+/-95 in PSL/mm(2), P<0.01), its deficiency had no influence. Both AT1- and AT2-knockouts showed significantly decreased BNP-mRNA concentrations (AT1: 21+/-6 vs. wildtype: 139+/-28 in PSL/mm(2), P<0.001; AT2: 8+/-2 vs. 19+/-3 in PSL/mm(2), P<0.05). These alterations correlate to reduced cardiac fibrosis in AT2-deficient animals, and an unchanged matrix content in ANG knockouts. CONCLUSIONS: Increased BNP-mRNA levels in hypertensive ANG-overexpressing mice and decreased BNP in hypotensive AT1-deficient animals suggest that this mRNA expression is blood pressure-dependent. However, the observed alterations of fibrosis and the unchanged BNP in hypotensive ANG knockouts and impaired BNP-mRNA expression in normotensive AT2-deficient mice demonstrate a direct interaction of the RAS and NPS that is fibrosis- rather than blood pressure-dependent.


Asunto(s)
Presión Sanguínea/fisiología , Fibrosis/genética , Fibrosis/fisiopatología , Regulación de la Expresión Génica , Miocardio/metabolismo , Péptido Natriurético Encefálico/biosíntesis , Péptido Natriurético Encefálico/genética , Animales , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Péptido Natriurético Encefálico/análisis , ARN Mensajero/análisis , ARN Mensajero/genética , Receptores de Angiotensina/deficiencia , Receptores de Angiotensina/genética
16.
Eur J Pharmacol ; 493(1-3): 161-5, 2004 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-15189777

RESUMEN

To explore the role of angiotensin II, we assessed hemodynamics and cardiac function in angiotensinogen-deficient mice in comparison to wild-type animals. Left ventricular end-diastolic diameter and wall thickness were evaluated by echocardiography and systolic and diastolic left ventricular function by pressure-volume relations using a micro-conductance catheter. Compared to wild-type animals, the angiotensinogen-deficient mice were hypotensive and showed impaired systolic function. The hearts were dilated, demonstrated by echocardiography and by a right-ward shift of the pressure-volume loops, but end-diastolic pressure, isovolumic relaxation (tau) and diastolic stiffness were unchanged. Afterload, however, was reduced leading to maintained cardiac output. Although a blockade of the renin-angiotensin system via angiotensin converting enzyme inhibitors or angiotensin AT1 receptor antagonist is beneficial after cardiac failure, the absence of angiotensin peptides during the ontogenesis leads to dilated cardiomyopathy.


Asunto(s)
Angiotensina II/deficiencia , Cardiomiopatía Dilatada/etiología , Modelos Animales de Enfermedad , Angiotensina II/genética , Angiotensinógeno/deficiencia , Angiotensinógeno/genética , Animales , Cardiomiopatía Dilatada/diagnóstico , Ecocardiografía/instrumentación , Ecocardiografía/métodos , Hemodinámica/fisiología , Hipotensión/etiología , Masculino , Ratones , Ratones Noqueados , Países Bajos , Receptores de Angiotensina/fisiología , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología
17.
Eur J Pharmacol ; 689(1-3): 147-53, 2012 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-22652430

RESUMEN

The G protein-coupled receptor Mas is a physiological antagonist of the angiotensin II type 1 receptor and is associated with angiotensin-(1-7) signaling. We investigated the effect of Mas-deficiency on blood pressure regulation under physiological conditions and salt load using radiotelemetry. Mas-knockout mice and their wild-type controls received a telemetry implant in the carotid artery. One week after surgery, animals were monitored for 3 days receiving normal diet (0.6% NaCl) followed by one-week high-salt diet (8% NaCl). Under same high-salt diet, another set of mice was placed in individual metabolic cages for 4 days. Basal mean arterial pressure, heart rate and locomotor activity displayed normal day-night rhythm in Mas-deficient mice. Mas-knockout mice were normotensive. High dietary NaCl ingestion did not alter heart rate or locomotor activity in both groups, but significantly increased night time mean arterial pressure in control mice whereas this increase was blunted in Mas-deficient mice. Baseline food and water intake and urine osmolality were not different between both genotypes. Under high-salt diet, water consumption and food intake were equally increased in wild-type controls and Mas-knockout, but urinary electrolytes and osmolality were significantly higher in Mas-knockout. Taken together, basal hemodynamic parameters are unchanged in Mas-knockout mice. In contrast to wild-type controls, telemetric mean arterial pressure measurement revealed salt resistance in Mas-deficient animals, probably due to their higher urinary NaCl excretion. This is the first direct proof that Mas blockade might be a new option in the treatment of salt-sensitive hypertension.


Asunto(s)
Eliminación de Gen , Hipertensión/inducido químicamente , Hipertensión/genética , Proteínas Proto-Oncogénicas/deficiencia , Proteínas Proto-Oncogénicas/genética , Receptores Acoplados a Proteínas G/deficiencia , Receptores Acoplados a Proteínas G/genética , Cloruro de Sodio Dietético/efectos adversos , Animales , Presión Sanguínea/genética , Femenino , Hipertensión/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proto-Oncogenes Mas
18.
Cardiovasc Res ; 86(3): 401-9, 2010 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-20071356

RESUMEN

AIMS: Our aim was to determine the contribution of the three angiotensin (Ang) II receptor subtypes (AT(1a), AT(1b), AT(2)) to coronary responsiveness, cardiac histopathology, and tissue Ang II levels using mice deficient for one, two, or all three Ang II receptors. METHODS AND RESULTS: Hearts of knockout mice and their wild-type controls were collected for histochemistry or perfused according to Langendorff, and kidneys were removed to measure tissue Ang II. Ang II dose-dependently decreased coronary flow (CF) and left ventricular systolic pressure (LVSP), and these effects were absent in all genotypes deficient for AT(1a), independently of AT(1b) and AT(2). The deletion of Ang II receptors had an effect neither on the morphology of medium-sized vessels in the heart nor on the development of fibrosis. However, the lack of both AT(1) subtypes was associated with atrophic changes in the myocardium, a reduced CF and a reduced LVSP. AT(1a) deletion alone, independently of the presence or absence of AT(1b) and/or AT(2), reduced renal Ang II by 50% despite a five-fold rise of plasma Ang II. AT(1b) deletion, on top of AT(1a) deletion (but not alone), further decreased tissue Ang II, while increasing plasma Ang II. In mice deficient for all three Ang II receptors, renal Ang II was located only extracellularly. CONCLUSION: The lack of both AT(1) subtypes led to a baseline reduction of CF and LVSP, and the effects of Ang II on CF and LVSP were found to be exclusively mediated via AT(1a). The lack of AT(1a) or AT(1b) does not influence the development or maintenance of normal cardiac morphology, whereas deficiency for both receptors led to atrophic changes in the heart. Renal Ang II levels largely depend on AT(1) binding of extracellularly generated Ang II, and in the absence of all three Ang II receptors, renal Ang II is only located extracellularly.


Asunto(s)
Angiotensina II/metabolismo , Miocardio/metabolismo , Receptor de Angiotensina Tipo 1/deficiencia , Receptor de Angiotensina Tipo 2/deficiencia , Angiotensina II/administración & dosificación , Angiotensina II/sangre , Animales , Atrofia , Circulación Coronaria , Fibrosis , Genotipo , Riñón/metabolismo , Masculino , Ratones , Ratones Noqueados , Miocardio/patología , Péptido Natriurético Encefálico/metabolismo , Perfusión , Fenotipo , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 2/genética , Función Ventricular Izquierda , Presión Ventricular , Remodelación Ventricular
19.
Congest Heart Fail ; 15(2): 75-81, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19379453

RESUMEN

To determine the diagnostic and prognostic value of natriuretic peptides in patients with Chagas' disease (CD), the authors first measured atrial (ANP), B-type (BNP), and C-type natriuretic peptide (CNP) and compared their diagnostic and prognostic capacity with that in other dilated cardiomyopathies (DCM). The CD and DCM patients were subdivided according to their New York Heart Association (NYHA) classification. Circulating ANP and more pronounced BNP, but not CNP, were increased in CD and DCM patients in relation to NYHA class. Importantly, ANP and BNP were already significantly elevated in CD patients without systolic ventricular dysfunction. All 3 natriuretic peptides were correlated with echocardiographic parameters in CD patients. While ANP and BNP have high predictive value for mortality and necessity for heart transplant in CD, CNP can not predict them. Thus, ANP and BNP rather than CNP could be used as valuable molecular markers to identify asymptomatic CD patients for early therapy and predict clinical outcomes.


Asunto(s)
Factor Natriurético Atrial/sangre , Cardiomiopatía Chagásica/sangre , Péptido Natriurético Encefálico/sangre , Péptido Natriurético Tipo-C/sangre , Adulto , Biomarcadores/sangre , Cardiomiopatía Dilatada/sangre , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/mortalidad , Cardiomiopatía Chagásica/diagnóstico por imagen , Cardiomiopatía Chagásica/mortalidad , Estudios de Cohortes , Ecocardiografía , Femenino , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/diagnóstico por imagen , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Estadística como Asunto , Tasa de Supervivencia , Disfunción Ventricular Izquierda/sangre , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/mortalidad
20.
PLoS One ; 4(4): e5406, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19404405

RESUMEN

Angiotensin (Ang) II mediates pathophysiologial changes in the kidney. Ang-(1-7) by interacting with the G protein-coupled receptor Mas may also have important biological activities.In this study, renal deficiency for Mas diminished renal damage in models of renal insufficiency as unilateral ureteral obstruction and ischemia/reperfusion injury while the infusion of Ang-(1-7) to wild-type mice pronounced the pathological outcome by aggravating the inflammatory response. Mas deficiency inhibited NF-kappaB activation and thus the elevation of inflammation-stimulating cytokines, while Ang-(1-7) infusion had proinflammatory properties in experimental models of renal failure as well as under basal conditions. The Ang-(1-7)-mediated NF-kappaB activation was Mas dependent but did not involve Ang II receptors. Therefore, the blockade of the NF-kappaB-activating properties of the receptor Mas could be a new strategy in the therapy of failing kidney.


Asunto(s)
Angiotensina I/farmacología , Inflamación/etiología , Enfermedades Renales/patología , Fragmentos de Péptidos/farmacología , Proteínas Proto-Oncogénicas/deficiencia , Receptores Acoplados a Proteínas G/deficiencia , Angiotensina I/administración & dosificación , Animales , Antihipertensivos/administración & dosificación , Antihipertensivos/farmacología , Citocinas , Inflamación/inducido químicamente , Enfermedades Renales/etiología , Ratones , Ratones Noqueados , FN-kappa B/antagonistas & inhibidores , Fragmentos de Péptidos/administración & dosificación , Proto-Oncogenes Mas , Daño por Reperfusión/patología
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