RESUMEN
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a major global health issue and a significant risk factor for atherosclerosis. Atherosclerosis in T2DM patients has been associated with inflammation, insulin resistance, hyperglycemia, dyslipidemia, and oxidative stress. Identifying molecular features of atherosclerotic plaques in T2DM patients could provide valuable insights into the pathogenesis of the disease. METHODS: The MASCADI (Arachidonic Acid Metabolism in Carotid Stenosis Plaque in Diabetic Patients) study aimed to investigate the increase of 2-arachidonoyl-lysophatidylcholine (2-AA-LPC) in carotid plaques from T2DM and control patients and to explore its association with plaque vulnerability as well as with blood and intra-plaque biomarkers altered during diabetes. RESULTS: In a population of elderly, polymedicated patients with advanced stage of atherosclerosis, we found that T2DM patients had higher systemic inflammation markers, such as high-sensitivity C-reactive protein (hsCRP) and IL-1ß, higher levels of oxysterols, increased triglyceride levels, and decreased HDL levels as compared to control patients. Furthermore, 2-AA-LPC was significantly enriched in plaques from diabetic patients, suggesting its potential role in diabetic atherosclerosis. Interestingly, 2-AA-LPC was not associated with systemic markers related to diabetes, such as hsCRP, triglycerides, or HDL cholesterol. However, it was significantly correlated with the levels of inflammatory markers within the plaques such as lysophospholipids and 25-hydroxycholesterol, strengthening the link between local inflammation, arachidonic acid metabolism and diabetes. CONCLUSION: Our study is in line with a key role for inflammation in the pathogenesis of diabetic atherosclerosis and highlights the involvement of 2-AA-LPC. Further research is needed to better understand the local processes involved in the alteration of plaque composition in T2DM and to identify potential therapeutic targets. TRIAL REGISTRATION: The MASCADI was registered on ClinicalTrials.gov (clinical registration number: NCT03202823).
Asunto(s)
Aterosclerosis , Enfermedades de las Arterias Carótidas , Diabetes Mellitus Tipo 2 , Placa Aterosclerótica , Anciano , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Proteína C-Reactiva , Ácido Araquidónico , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/epidemiología , Inflamación/diagnósticoRESUMEN
BACKGROUND AND AIMS: Diabetes is associated with an accelerated development of atherosclerosis. Specific mechanisms related to diabetes and hyperglycemia may play a role in this process. In particular, alterations of arachidonic acid (AA) metabolism have been reported. Our main goal was to investigate for differences in the concentration of LTB4 and RvD1 as well as selected cyclooxygenase-derived mediators in carotid plaques from diabetic and non-diabetic patients. We also aimed to analyze the relationship between omega 6 and omega 3 Poly-Unsaturated Fatty acids (PUFAs) content in the plaques and the concentrations of these lipid mediators. METHODS: 29 type 2 diabetic patients and 30 control patients admitted for surgical treatment of carotid stenosis were enrolled in the present study. Carotid plaques were harvested for in-depth lipidomic profiling. RESULTS: No differences for LTB4 or other lipid mediators were observed between diabetic and non-diabetic patients. RvD1 levels were below the threshold of quantification in most of the samples. A significant correlation was found between LTB4 and 5(S)-HETE levels. Omega 3 enrichment was not significantly different between control and diabetic plaques. There was a negative correlation between DHA/AA ratio and the level of 5(S)-HETE while there was a positive association with TXB2 and PGD2 concentrations. CONCLUSION-PERSPECTIVES: Our results does not support the hypothesis of a specific involvement of LTB4 or COX-derived mediators in diabetic atherosclerosis. The relationship between DHA enrichment and the concentrations of specific inflammatory mediators within the plaque is of interest and will need to be confirmed in larger studies.
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Aterosclerosis , Diabetes Mellitus Tipo 2 , Placa Aterosclerótica , Diabetes Mellitus Tipo 2/complicaciones , Eicosanoides/metabolismo , Humanos , Ácidos Hidroxieicosatetraenoicos , Leucotrieno B4RESUMEN
INTRODUCTION: Aneurysms of the ascending aorta (AA) correspond to a dilatation of the ascending aorta that progressively evolves over several years. The main complication of aneurysms of the ascending aorta is type A aortic dissection, which is associated with very high rates of morbidity and mortality. Prophylactic ascending aorta replacement guidelines are currently based on maximal AA diameter. However, this criterion is imperfect. Stretching tests on the aorta carried out ex-vivo make it possible to determine the elastic properties of healthy and aneurysmal aortic fragments (tension test, resistance before rupture). For several years now, cardiac magnetic resonance imaging (MRI) has provided another means of evaluating the elastic properties of the aorta. This imaging technique has the advantage of being non-invasive and of establishing aortic compliance (local measurement of stiffness) without using contrast material by measuring the variation of the aortic surface area during the cardiac cycle, and pulse wave velocity (overall stiffness of the aorta). MATERIALS AND METHODS: Prospective single-center study including 100 patients with ascending aortic aneurysm requiring surgery. We will perform preoperative cine-MRI and biomechanical laboratory stretching tests on aortic samples collected during the cardiac procedure. Images will be acquired with a 3T MRI with only four other acquisitions in addition to the conventional protocol. These additional sequences are a Fast Low Angle Shot (FLASH)-type sequence performed during a short breath-hold in the transverse plane at the level of the bifurcation of the pulmonary artery, and phase-contrast sequences that encodes velocity at the same localization, and also in planes perpendicular to the aorta at the levels of the sino-tubular junction and the diaphragm for the descending aorta. For ex-vivo tests, the experiments will be carried out by a biaxial tensile test machine (ElectroForce®). Each specimen will be stretched with 10 times of 10% preconditioning and at a rate of 10 mm/min until rupture. During the experiment, the tissue is treated under a 37°C saline bath. The maximum elastic modulus from each sample will be calculated. RESULTS: The aim of this study is to obtain local patient-specific elastic modulus distribution of the ascending aorta from biaxial tensile tests and to assess elastic properties of the aorta using MRI, then to evaluate the correlation between biaxial tests and MRI measurements. DISCUSSION: Our research hypothesis is that there is a correlation between the evaluation of the elastic properties of the aorta from cardiac MRI and from stretching tests performed ex-vivo on aorta samples collected during ascending aorta replacement.
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Aorta/patología , Aneurisma de la Aorta/patología , Elasticidad , Imagen por Resonancia Cinemagnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Fenómenos Biomecánicos , Contencion de la Respiración , Humanos , Estudios Prospectivos , Análisis de la Onda del PulsoRESUMEN
BACKGROUND: To evaluate the role of aortic root remodeling with external aortic annuloplasty (ARREAA) in acute type A aortic dissection (AAAD). METHODS: From May 2011 to May 2020, 59 patients out of 240 with AAAD underwent ARREAA. Data were retrospectively collected and analyzed. RESULTS: The mean age was 61.4 ± 8.6 years and 43 patients were males (73%). Hemiarch and total arch replacement were performed in 37 (62.7%) and 14 (23.7%) patients. An aortic valvuloplasty was performed in seven patients (11.8%). Five patients (8.5%) required coronary artery bypass graft. Re-exploration for bleeding was required in six patients (10.1%). The 30-day mortality rate was 18.6%. Preoperative hemodynamic instability (odds ratio [OR] = 8.57, 95% confidence interval [CI] = 1.57-46.71; p = 0.013), consciousness disorder (OR = 19.18, 95% CI = 3.02-121.72]; p = 0.002) or myocardial ischemia (OR = 6.28, 95% CI = 1.27-31.10; p = 0.013) were significantly associated with postoperative mortality. No patient was reoperated for aortic valve during the postoperative period. One patient suffered a stroke postoperatively with partial recovery. Kidney failure requiring temporary dialysis occurred in 12 patients (20.3%). At discharge, a transthoracic echocardiogram showed moderate aortic regurgitation (AR; grade 2) in two patients. During follow-up (mean = 58.4 ± 32.4 months), three patients died. The rate of mortality was 6.2%. Actuarial survival at 5 years was 76.3%. No patient required reoperation on the proximal aorta or aortic valve. At 4 years, freedom from any aortic valve or root reintervention and AR > 2 were both 100%. CONCLUSION: In a center with expertise in valve-sparing procedures, ARREAA is a reasonable option in the surgical management of AAAD in selected patients. This technique stabilizes the aortic annulus and preserves root anatomy for durable outcomes.
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Disección Aórtica , Insuficiencia de la Válvula Aórtica , Implantación de Prótesis Vascular , Anciano , Disección Aórtica/cirugía , Aorta/cirugía , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Low-grade inflammation is constitutive of atherosclerosis, and anti-inflammatory therapy inhibiting interleukin-1ß (IL-1ß) reduces the rate of cardiovascular events. While cholesterol accumulation in atheroma plaque and macrophages is a major driver of the inflammatory process, the role of the LXR cholesterol sensors remains to be clarified. Murine and human macrophages were treated with LXR agonists for 48 h before Toll-like receptor (TLR) stimulation. Unexpectedly, we observe that, among other cytokines, LXR agonists selectively increase IL1B mRNA levels independently of TLR activation. This effect, restricted to human macrophages, is mediated by activation of HIF-1α through LXR. Accordingly, LXR agonists also potentiate other HIF-1α-dependent pathways, such as glycolysis. Treatment of human macrophages with carotid plaque homogenates also leads to induction of IL1B in an LXR-dependent manner. Thus, our work discloses a mechanism by which cholesterol and oxysterols trigger inflammation in atherosclerosis. This suggests perspectives to target IL-1ß production in atherosclerotic patients.
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Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Interleucina-1beta/biosíntesis , Receptores X del Hígado/metabolismo , Macrófagos/metabolismo , Animales , Aterosclerosis/metabolismo , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Receptores X del Hígado/agonistas , Receptores X del Hígado/antagonistas & inhibidores , Ratones , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
OBJECTIVE: The aim of our study was to evaluate the impact of aortic root replacement by graft on the elastic properties of the descending thoracic aorta using cardiac magnetic resonance imaging (MRI) and automatic post-processing. MATERIALS AND METHODS: Nineteen patients were operated for an aortic root aneurysm. Cardiac MRI was performed before and after surgery to measure aortic compliance. Images were acquired on a 1.5 T MRI with a conventional aortic MRI protocol plus one additional kinetic sequence orientated perpendicularly to the aorta at the level of pulmonary trunk. The contours of the ascending and descending aortas were detected automatically for each phase with homemade software. RESULTS: Mean time between surgical procedure and earliest post-operative MRI was 18.2 ± 7.1 months. There was no significant difference between the pre- and earliest post-operative mean descending aorta areas and no significant modification in descending aortic compliance after aortic root replacement (1.43 ± 0.84 vs 1.37 ± 0.58 mm2/mmHg, p = 0.47). Pre- and post-operative systolic and diastolic blood pressure were similar. There was a significant decrease in ascending aortic compliance after surgery (2.52 ± 1.24 vs 0.91 ± 0.52 mm2/mmHg; p < 0.0001). DISCUSSION: The aortic root replacement by graft was not associated with changes in elastic properties of the descending aorta at short term. CLINICAL REGISTRATION NUMBER: NCT03817008.
Asunto(s)
Aorta Torácica , Aorta , Presión Sanguínea , Humanos , Imagen por Resonancia MagnéticaRESUMEN
BACKGROUND: Despite current progress, the prognosis of critical limb ischemia (CLI) remains poor. The ageing of the population, the increasing prevalence of diabetes mellitus, and the stability of tobacco use will increase the prevalence of CLI. CLI patients have risk factors for malnutrition, and the impact of malnutrition on morbidity and mortality has been demonstrated in the general population. However, we have little information on the consequences of undernutrition in the CLI population. The aim of this study is to assess the impact of malnutrition on the early outcomes in CLI patients. METHODS: This is a double-center prospective study that included all consecutive hospitalized patients with CLI. All patients were screened for malnutrition and divided into 2 groups: severe malnourished patients (group A) and moderate malnourished and well-nourished (group B). This distribution was based on age-indexed clinical and biological data and the patient's general condition: the Nutritional Risk Index for patients younger than 75 years, the Mini Nutritional Assessment, or the Geriatric Nutritional Risk Index for those older than 75 years. The primary end point was defined as the rate of 30-day death. Outcomes were compared in a univariate analysis. Stepwise logistic regression was used for the multivariate analysis. Variables with a P value <0.2 in the univariate analysis were introduced in the multivariate model. RESULTS: We included 106 patients. The prevalence of malnutrition was 75.5%, divided into moderate malnutrition (51.9%) and severe malnutrition (23.6%). Six patients (24%) died in group A compared with 8 in group B (4.9%) (P = 0.01). By univariate analysis, severe malnutrition was the only factor associated with death at 30 days. By stepwise logistic regression, severe malnutrition (odds ratio 6.1, 95% confidence interval 1.6-23.7, P = 0.006) was found to be the significant risk factors for death at 30 days. CONCLUSIONS: This study is the first to demonstrate prospectively the major importance of malnutrition in the early prognosis of CLI patients.
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Fármacos Cardiovasculares/uso terapéutico , Procedimientos Endovasculares , Isquemia/terapia , Desnutrición/fisiopatología , Estado Nutricional , Enfermedad Arterial Periférica/terapia , Injerto Vascular , Anciano , Anciano de 80 o más Años , Amputación Quirúrgica , Fármacos Cardiovasculares/efectos adversos , Distribución de Chi-Cuadrado , Enfermedad Crítica , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Femenino , Francia/epidemiología , Evaluación Geriátrica , Humanos , Isquemia/diagnóstico , Isquemia/mortalidad , Isquemia/fisiopatología , Tiempo de Internación , Recuperación del Miembro , Modelos Logísticos , Masculino , Desnutrición/diagnóstico , Desnutrición/mortalidad , Análisis Multivariante , Evaluación Nutricional , Oportunidad Relativa , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/mortalidad , Enfermedad Arterial Periférica/fisiopatología , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento , Injerto Vascular/efectos adversos , Injerto Vascular/mortalidadRESUMEN
BACKGROUND: Genotyping studies have shown heterogeneity of Candida albicans flora in patients with human immunodeficiency virus infection, with possible co-existence of multiple clones with distinct resistance patterns. We report the result of a prospective study aimed at investigating the dynamics and heterogeneity of C. albicans flora in patients with de novo acute leukemia. DESIGN AND METHODS: Between 2001 and 2003, 66 consecutive adults with newly diagnosed acute leukemia were monitored for Candida colonization. From 19 patients with repeated multi-site C. albicans colonization, eight were randomly selected and multiple isolates from each individual mucosal site were genotyped sequentially over time using microsatellite markers. RESULTS: Despite topical use of polyenes, 60.6% of the patients were colonized repeatedly and at multiple sites. Altogether, 2,730 peripheral samples were cultured, 379 (13.9%) of which yielded yeasts. C. albicans was the most common species recovered (68%). From eight randomly selected patients colonized with C. albicans, 429 isolates were genotyped. Seven patients carried a unique genotype which was identical in all body niches and over the period of study. In one case, minor genotypic differences were observed. None of the patients shared C. albicans clones with identical genotypic profiles. Candidemia occurred in one of eight patients and the blood strain genotype did not differ from those of colonizing isolates. The genotypic profile was not altered by topical and/or systemic use of antifungal agents in any of the patients. CONCLUSIONS: In patients with de novo acute leukemia, genetic evolution of the colonizing C. albicans flora and selection of variants or replacement of the original strain upon antifungal drug pressure or nosocomial transmission are rare events.
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Candida albicans/genética , Candidiasis/microbiología , Genoma Fúngico , Leucemia/complicaciones , Neutropenia/complicaciones , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Candida albicans/efectos de los fármacos , Candidiasis/etiología , Farmacorresistencia Fúngica/genética , Femenino , Variación Genética , Genotipo , Humanos , Huésped Inmunocomprometido , Leucemia/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Agonistas Mieloablativos/efectos adversos , Agonistas Mieloablativos/uso terapéutico , Neutropenia/inducido químicamente , Especificidad de Órganos , Aislamiento de Pacientes , MuestreoRESUMEN
BACKGROUND: Some oxysterols are identified in atheromatous plaques and in plasma of atherosclerotic patients. We asked whether they might modulate cytokine secretion on human monocytic cells. In healthy and atherosclerotic subjects, we also investigated the relationships between circulating levels of C-reactive protein (CRP), conventional markers of hyperlipidemia, some oxysterols (7beta-hydroxycholesterol, 7-ketocholesterol, and 25-hydroxycholesterol), and various cytokines. METHODS: Different flow cytometric bead-based assays were used to quantify some cytokines (IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, G-CSF, GM-CSF, IFN-gamma, MCP-1, MIP-1beta, or TNF-alpha) in the culture media of oxysterol-treated U937 and THP-1 cells, and in the sera of healthy and atherosclerotic subjects. CRP and markers of hyperlipidemia were determined with routine analytical methods. Oxysterols were quantified by gas chromatography/mass spectrometry. Flow cytometric and biochemical methods were used to measure IL-8 mRNA levels, intracellular IL-8 content, and protein phosphorylation in the mitogenic extracellular kinase/extracellular signal-regulated kinase1/2 (MEK/ERK1/2) signaling pathway. RESULTS: All oxysterols investigated are potent in vitro inducers of MCP-1, MIP-1beta, TNF-alpha, and/or IL-8 secretion, the latter involving the MEK/ERK1/2 cell signaling pathway. In healthy and atherosclerotic subjects, no relationships were found between cytokines (IL-8, IL-1beta, IL-6, IL-10, TNF-alpha, IL-12, and MCP-1), CRP, conventional markers of hyperlipidemia, and oxysterols. However, in patients with arterial disorders of the lower limbs, small but statistically significant differences in the circulating levels of CRP, TNF-alpha, and IL-10 were observed comparatively to healthy subjects and according to the atherosclerotic stage considered. CONCLUSIONS: Flow cytometric bead-based assays are well adapted to measure variations of cytokine secretion in the culture media of oxysterol-treated cells and in the sera of healthy and atherosclerotic subjects. They underline the in vitro proinflammatory properties of oxysterols and may permit to distinguish healthy and atherosclerotic subjects, as well as various atherosclerotic stages.
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Arteriosclerosis/inmunología , Citocinas/análisis , Citometría de Flujo/métodos , Monocitos/inmunología , Esteroles/farmacología , Anciano , Muerte Celular , Medios de Cultivo , Citocinas/sangre , Femenino , Humanos , Mediadores de Inflamación/análisis , Mediadores de Inflamación/sangre , Interleucina-8/metabolismo , Masculino , Microesferas , Persona de Mediana Edad , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Modelos Biológicos , Monocitos/citología , Fosforilación/efectos de los fármacos , Esteroles/metabolismo , Células TH1/inmunología , Células Tumorales Cultivadas , Células U937RESUMEN
The cardiovascular role of angiotensin-(1-7), especially in the functional and metabolic alterations associated with ischemia-reperfusion (IR), is still not clearly defined. Our objective was to evaluate the cardiac effects of angiotensin-(1-7), the receptors involved, and their relationships with NADPH oxidase activation under non-ischemic conditions and, during an ischemia-reperfusion sequence. Isolated perfused rat hearts underwent 45 min of non-ischemic perfusion, or 30 min of global ischemia followed by 30 min of reperfusion. Angiotensin-(1-7) and/or AT1 receptor blocker losartan or angiotensin-(1-7) receptor antagonist (D-Ala7)-angiotensin-(1-7) were perfused. Our results showed that angiotensin-(1-7) was without effect at low concentrations (10(-10) to 10(-7) M). At a pharmacological concentration, 0.5 microM angiotensin-(1-7) induced vasoconstriction, which was antagonised by losartan. After ischemia, we noted a partial recovery of functional parameters, which was not modified by any of the treatments. The expression of AT1 receptor mRNA was increased by ischemia-reperfusion, except in (D-Ala7)-angiotensin-(1-7) treated hearts. Angiotensin-(1-7) further increased the AT1 expression. NADPH oxidase activity was enhanced in 0.5 microM angiotensin-(1-7)-treated hearts subjected to ischemia-reperfusion, this effect was totally reversed by losartan. This is the first time that it has been shown that, in the heart, angiotensin-(1-7) at pharmacological concentration activates NADPH oxidase, an enzyme thought to be involved in several angiotensin II effects.
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Angiotensina I/farmacología , Antihipertensivos/farmacología , Corazón/efectos de los fármacos , Isquemia Miocárdica/metabolismo , NADPH Oxidasas/metabolismo , Fragmentos de Péptidos/farmacología , Receptor de Angiotensina Tipo 1/metabolismo , Reperfusión , Angiotensina II/análogos & derivados , Angiotensina II/farmacología , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Animales , Relación Dosis-Respuesta a Droga , Activación Enzimática , Técnicas In Vitro , Losartán/farmacología , Masculino , Miocardio/enzimología , Ratas , Ratas WistarRESUMEN
Vitamin C is considered to be a very efficient water-soluble antioxidant, for which several new cardiovascular properties were recently described. The aim of this study was to determine in vivo the effects of a severe depletion of vitamin C on cardiac and vascular variables and reperfusion arrhythmias. For this purpose, we used a mutant strain of Wistar rats, osteogenic disorder Shionogi (ODS). After 15 d of consuming a vitamin C-deficient diet, ODS rats had a 90% decrease in plasma and tissue levels of ascorbate compared with ODS vitamin C-supplemented rats and normal Wistar rats. However, plasma antioxidant capacity, proteins, alpha-tocopherol, urate, catecholamines, lipids, and nitrate were not influenced by the vitamin C deficiency in ODS rats. Moreover, there was no difference between ODS vitamin C-deficient and -supplemented rats in heart rate and arterial pressure. After 5 min of an in vivo regional myocardial ischemia, various severe arrhythmias were observed, but their intensities were not modified by vitamin C in vitamin C-deficient ODS rats. The vascular reactivity, measured in vitro on thoracic arteries, was not altered by ascorbate deficiency in ODS rats. These unexpected results suggest that unidentified compensatory mechanisms play a role in maintaining normal cardiac function and vascular reactivity in vitamin C-deficient rats.
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Deficiencia de Ácido Ascórbico/complicaciones , Enfermedades Óseas/genética , Enfermedades Cardiovasculares/etiología , Osteogénesis , Acetilcolina/farmacología , Animales , Aorta , Arritmias Cardíacas/etiología , Ácido Ascórbico/administración & dosificación , Deficiencia de Ácido Ascórbico/fisiopatología , Presión Sanguínea , Enfermedades Óseas/fisiopatología , Enfermedades Cardiovasculares/tratamiento farmacológico , Dieta , Epinefrina/sangre , Frecuencia Cardíaca , Masculino , Contracción Muscular/efectos de los fármacos , Isquemia Miocárdica/fisiopatología , Reperfusión Miocárdica/efectos adversos , Norepinefrina/sangre , Fenilefrina/farmacología , Ratas , Ratas Mutantes , Ratas Wistar , alfa-Tocoferol/sangreRESUMEN
In the left ventricle subjected to pressure overload activity, the antioxidant enzymes increased at the hyperfunctional stage. During the transition to heart failure, these enzymes are down-regulated, oxidative stress increases, and apoptosis progresses. Maladaptative activation of the antioxidant enzymes at an early stage may contribute to the intrinsic vulnerability of right ventricle to pressure overload. The authors studied changes in expression and activity of the enzymes manganese and copper-zinc superoxide dismutases, glutathione peroxidase, and catalase in the right ventricle of rat following induction of pulmonary hypertension by injection of monocrotaline. Increase in the manganese superoxide dismutase was delayed to the late failing stage, activity of glutathione peroxidase was depressed throughout, and only catalase was activated at the early stage before returning to control levels. This inability to activate antioxidant enzymes may contribute to the deleterious consequences of pressure overload on right ventricle systolic function.
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Antioxidantes/metabolismo , Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Insuficiencia Cardíaca/metabolismo , Ventrículos Cardíacos/metabolismo , Hipertrofia Ventricular Derecha/metabolismo , Superóxido Dismutasa/metabolismo , Animales , Antioxidantes/análisis , Secuencia de Bases , Catalasa/análisis , Glutatión Peroxidasa/análisis , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/química , Ventrículos Cardíacos/fisiopatología , Hipertrofia Ventricular Derecha/etiología , Hipertrofia Ventricular Derecha/fisiopatología , Modelos Animales , Estrés Oxidativo/fisiología , Presión/efectos adversos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/efectos adversos , Análisis de Secuencia de ARN , Superóxido Dismutasa/análisisRESUMEN
Atherosclerosis involves inflammatory processes, as well as cytotoxic and oxidative reactions. In atherosclerotic plaques, these phenomena are revealed by the presence of dead cells, oxidized lipids, and oxidative DNA damage, but the molecules triggering these events are still unknown. As 7 beta-hydroxycholesterol and 7-ketocholesterol, which are present at elevated concentrations in atherosclerotic lesions, are strongly cytotoxic and pro-oxidative, their effects were determined on cell death, superoxide anion and nitric oxide production, lipid peroxidation, and oxidative DNA damage. 7-Ketocholesterol- and 7 beta-hydroxycholesterol-induced cell death leads to a loss of mitochondrial potential, to increased permeability to propidium iodide, and to morphological nuclear changes (swelling, fragmentation, and/or condensation of nuclei). These effects are preceded by the formation of cytoplasmic monodansylcadaverine-positive structures and are associated with a rapid enhancement of cells overproducing superoxide anions, a decrease in cells producing nitric oxide, lipid peroxidation (formation of malondialdehyde and 4-hydroxynonenal adducts, low ratio of [unsaturated fatty acids]/[saturated fatty acids]) as well as oxidative DNA damage (8-oxoguanine formation). Noteworthy, none of the cytotoxic features previously observed with 7 beta-hydroxycholesterol and 7-ketocholesterol were noted with cholesterol, 7 beta-hydroxycholesteryl-3-oleate and 7-ketocholesteryl-3-oleate, with the exception of a slight increase in superoxide anion production with 7 beta-hydroxycholesteryl-3-oleate. This finding supports the theory that 7 beta-hydroxycholesterol and 7-ketocholesterol could induce cytotoxic and oxidative processes observed in atherosclerotic lesions and that esterification of these compounds may contribute to reducing atherosclerosis progression.
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Cadaverina/análogos & derivados , Hidroxicolesteroles/metabolismo , Hidroxicolesteroles/toxicidad , Cetocolesteroles/metabolismo , Cetocolesteroles/toxicidad , Ácido Oléico/metabolismo , Arteriosclerosis/etiología , Arteriosclerosis/metabolismo , Arteriosclerosis/prevención & control , Cadaverina/metabolismo , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Esterificación , Humanos , Hidroxicolesteroles/química , Cetocolesteroles/química , Peroxidación de Lípido/efectos de los fármacos , Óxido Nítrico/biosíntesis , Oxidación-Reducción , Superóxidos/metabolismo , Células U937RESUMEN
The role of angiotensin II in myocardial ischaemia-reperfusion is not clearly defined. In this respect, the involvement of NADPH oxidase remains to be determined. The aim of this study was 1) to evaluate the cardiac effects of angiotensin AT(1) receptor stimulation in non-ischaemic conditions of perfusion or during ischaemia-reperfusion, and 2) to measure the concomitant activation of NADPH oxidase in isolated rat hearts perfused with angiotensin II and/or Losartan. In non-ischaemic hearts, angiotensin II induced rapid and prolonged vasoconstrictive and negative inotropic effects. Ischaemia-reperfusion increased the mRNA expression of AT(1) and AT(2) receptors. During reperfusion, angiotensin II reduced the incidence of arrhythmias and the lactate dehydrogenase released, and increased NADPH oxidase mRNA expression and enzyme activity. Losartan co-administration totally antagonised the effects of angiotensin II. Our study demonstrates that ischaemia-reperfusion induces adaptative cardiac modifications, which allow exogenously added angiotensin II to stimulate myocardial NADPH oxidase through angiotensin AT(1) receptor activation.