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1.
Am Heart J Plus ; 44: 100413, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38947733

RESUMO

The American Heart Association (AHA) has devised Life's Essential 8, a set of eight evidence-based health behaviors that play a crucial role in optimizing cardiovascular health and overall well-being. In addition to Life's Essential 8, enhanced screening for Cardiovascular-Kidney-Metabolic (CKM) Syndrome risk factors into routine athlete screening also provides a more comprehensive approach for ensuring athlete safety and long-term health. Incorporating Life's Essential 8 and CKM Syndrome metrics into athlete health evaluations will improve the sports performance of athletes and help optimize their long-term health.

2.
JACC Case Rep ; 29(14): 102397, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38952423

RESUMO

Right ventricular outflow tract (RVOT) obstruction is a rare complication of ventricular hypertrophy in patients with hypertrophic cardiomyopathy (HCM). This study presents an unusual case of a patient with HCM with severe RVOT obstruction that was relieved successfully through the use of mavacamten.

3.
Curr Sports Med Rep ; 23(7): 270-274, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38941549

RESUMO

ABSTRACT: Hypertrophic cardiomyopathy is a genetic heart condition occurring in up to 1 in 200 patients in the United States, many of whom are young and otherwise healthy. This condition puts those affected at increased risk for adverse cardiac outcomes, including sudden cardiac arrest and death, with particular concern for this to occur during exercise and other forms of exertion. Recent studies aimed at evaluating the risk of exercise in hypertrophic cardiomyopathy patients have suggested that moderate and even vigorous exercise may be safe for certain patients. Clinical guidelines are changing to reflect this recent information and to encourage a shared decision-making approach, which can allow more hypertrophic cardiomyopathy patients to participate in health-promoting exercise activities.


Assuntos
Cardiomiopatia Hipertrófica , Morte Súbita Cardíaca , Exercício Físico , Humanos , Cardiomiopatia Hipertrófica/terapia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Exercício Físico/efeitos adversos
4.
Curr Sports Med Rep ; 23(2): 30-31, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38315427
5.
JACC Case Rep ; 4(17): 1094-1097, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36124149

RESUMO

Swimming-induced pulmonary edema is a leading cause of triathlon-associated emergencies and death. Cold water immersion, female sex, age>50, and wetsuit compression are associated risk factors. Pathophysiology is due to increased central blood pooling, leading to increased pulmonary capillary wedge pressure. Treatment is focused on prevention; however, recurrence is common. (Level of Difficulty: Intermediate.).

6.
Methodist Debakey Cardiovasc J ; 17(4): 48-59, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34824681

RESUMO

Early identification and mitigation of sex-specific cardiovascular disease risk factors is a potential trajectory-changing strategy to improve lifelong cardiovascular health in women. These sex-specific risk factors include adverse pregnancy outcomes, polycystic ovarian syndrome, and premature menopause. We start by discussing the impact and management of risk factors for adverse pregnancy outcomes as an upstream intervention for cardiovascular disease risk reduction and then address the long-term effect and mitigation of sex-specific risk factors for cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Gravidez , Medição de Risco , Fatores de Risco , Útero
8.
JMIR Med Inform ; 7(4): e14756, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31579025

RESUMO

BACKGROUND: Patients hospitalized with heart failure suffer the highest rates of 30-day readmission among other clinically defined patient populations in the United States. Investigation into the predictability of 30-day readmissions can lead to clinical decision support tools and targeted interventions that can help care providers to improve individual patient care and reduce readmission risk. OBJECTIVE: This study aimed to develop a dynamic readmission risk prediction model that yields daily predictions for patients hospitalized with heart failure toward identifying risk trajectories over time and identifying clinical predictors associated with different patterns in readmission risk trajectories. METHODS: A two-stage predictive modeling approach combining logistic and beta regression was applied to electronic health record data accumulated daily to predict 30-day readmission for 534 hospital encounters of patients with heart failure over 2750 patient days. Unsupervised clustering was performed on predictions to uncover time-dependent trends in readmission risk over the patient's hospital stay. We used data collected between September 1, 2013, and August 31, 2015, from a community hospital in Maryland (United States) for patients with a primary diagnosis of heart failure. Patients who died during the hospital stay or were transferred to other acute care hospitals or hospice care were excluded. RESULTS: Readmission occurred in 107 (107/534, 20.0%) encounters. The out-of-sample area under curve for the 2-stage predictive model was 0.73 (SD 0.08). Dynamic clinical predictors capturing laboratory results and vital signs had the highest predictive value compared with demographic, administrative, medical, and procedural data included. Unsupervised clustering identified four risk trajectory groups: decreasing risk (131/534, 24.5% encounters), high risk (113/534, 21.2%), moderate risk (177/534, 33.1%), and low risk (113/534, 21.2%). The decreasing risk group demonstrated change in average probability of readmission from admission (0.69) to discharge (0.30), whereas the high risk (0.75), moderate risk (0.61), and low risk (0.39) groups maintained consistency over the hospital course. A higher level of hemoglobin, larger decrease in potassium and diastolic blood pressure from admission to discharge, and smaller number of past hospitalizations are associated with decreasing readmission risk (P<.001). CONCLUSIONS: Dynamically predicting readmission and quantifying trends over patients' hospital stay illuminated differing risk trajectory groups. Identifying risk trajectory patterns and distinguishing predictors may shed new light on indicators of readmission and the isolated effects of the index hospitalization.

9.
Amyloid ; 25(3): 174-179, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30169971

RESUMO

INTRODUCTION: Diagnostic delay of cardiac amyloidosis (CAm) continues to challenge clinicians. We investigated features associated with delay and ascertained if a diagnostic delay had negative implications for the patient. METHODS: We performed a retrospective chart review identifying 82 subjects with biopsy-proven and mass-spectrometry-identified CAm with clinical and epidemiologic data including first potential symptom of amyloidosis. Pathology slides were scored for extent of amyloid. Robust statistical analyses including generalized linear and ordered logistic regression analysis were performed. RESULTS: There was a 22 month (median) delay in diagnosis, more pronounced (34 months) in subjects with transthyretin (ATTR) amyloidosis. Seven factors predict a delayed diagnosis including ATTR amyloid type (ratio =2.17, 95% CI 1.31-3.59), having carpal tunnel syndrome (2.13, CI 1.49-3.03) and age <70 at first symptom (1.85, CI 1.30-2.61). Individuals with delays of 1+ years had higher levels of NT proBNP (4451 vs. 2559 pg/mL, p = .016) and longer PR intervals (225 vs. 162 ms, p < .001) at the time of diagnosis. CONCLUSIONS: Diagnostic delays negatively affect cardiac function. Of the predictive clinical features, carpal tunnel syndrome was frequent and its presence should lead to a more aggressive analysis for CAm in the appropriate clinical settings.


Assuntos
Amiloidose/diagnóstico , Diagnóstico Tardio , Idoso , Neuropatias Amiloides Familiares/diagnóstico , Biópsia , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Miocárdio/patologia , Estudos Retrospectivos
10.
J Card Fail ; 23(8): 652-655, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28624653

RESUMO

BACKGROUND: The presence of giant ring mitochondria on endomyocardial biopsy is rarely reported and does not have a well-defined differential diagnosis. METHODS: We report the case of a 54-year-old man with heart failure and preserved ejection fraction and left ventricular hypertrophy, initially thought to have an infiltrative cardiomyopathy. RESULTS: The patient was found to have extensive vacuolization caused by giant ring mitochondria on endomyocardial biopsy. Mitochondrial genetic testing revealed an A3243G mutation in the MT-TL1 gene, which is a mitochondrial encoded transfer RNA-leucine molecule. CONCLUSIONS: Mitochondrial disease should be considered in patients presenting with unexplained cardiomyopathy and skeletal muscle, cerebral, or metabolic abnormalities. In this case, the presence of unexpected extensive cardiomyocyte vacuolization and giant, ring-shaped mitochondria on endomyocardial biopsy prompted mitochondrial genetic testing, which ultimately resulted in the correct diagnosis and treatment.


Assuntos
Genes Mitocondriais/genética , Insuficiência Cardíaca/genética , Leucoencefalopatias/genética , Mutação/genética , RNA de Transferência de Leucina/genética , Insuficiência Cardíaca/diagnóstico por imagem , Humanos , Leucoencefalopatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Linhagem
11.
Med Gas Res ; 7(1): 1-8, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28480026

RESUMO

Exercise training confers sustainable protection against ischemia/reperfusion injury. However, the mechanism by which this process occurs is not fully understood. Previously, it was shown that ß3-adrenergic receptors (ß3-ARs) play a critical role in regulating the activation of endothelial nitric oxide synthase (eNOS) in response to exercise and play a critical role in exercise-mediated cardioprotection. Intriguingly, a deficiency in ß3-ARs led to increased myocardial injury following exercise training. The purpose of the current study was to determine mechanisms by which ß3-ARs are linked to eNOS activation and to determine the mechanism responsible for the exacerbated ischemia/reperfusion injury displayed by ß3-AR deficient (ß3-AR KO) mice after exercise training. Wild-type (n = 37) and ß3-AR KO (n = 40) mice were subjected to voluntary wheel running for 4 weeks. Western blot analysis revealed that neither protein kinase B nor protein kinase A linked ß3-ARs to eNOS following exercise training. However, analysis revealed a role for AMP-activated protein kinase (AMPK). Specifically, exercise training increased the phosphorylation of AMPK in the hearts of wild-type mice, but failed to do so in the hearts of ß3-AR KO mice. Additional studies revealed that exercise training rendered eNOS less coupled and increased NOS-dependent superoxide levels in ß3-AR KO mice. Finally, supplementing ß3-AR KO mice with the eNOS coupler, tetrahydrobiopterin, during the final week of exercise training reduced myocardial infarction. These findings provide important information that exercise training protects the heart in the setting of myocardial ischemia/reperfusion injury by activating and coupling eNOS via the stimulation of a ß3-AR-AMPK signaling pathway.

13.
J Mol Cell Cardiol ; 62: 8-17, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23643588

RESUMO

RATIONALE: Stimulation of ß3-adrenoreceptors (ß3-AR) blunts contractility and improves chronic left ventricular function in hypertrophied and failing hearts in a neuronal nitric oxide synthase (nNOS) dependent manner. nNOS can be regulated by post-translational modification of stimulatory phosphorylation residue Ser1412 and inhibitory residue Ser847. However, the role of phosphorylation of these residues in cardiomyocytes and ß3-AR protective signaling has yet to be explored. OBJECTIVE: We tested the hypothesis that ß3-AR regulation of myocyte stress requires changes in nNOS activation mediated by differential nNOS phosphorylation. METHODS AND RESULTS: Endothelin (ET-1) or norepinephrine induced hypertrophy in rat neonatal ventricular cardiomyocytes (NRVMs) was accompanied by increased ß3-AR gene expression. Co-administration of the ß3-AR agonist BRL-37433 (BRL) reduced cell size and reactive oxygen species (ROS) generation, while augmenting NOS activity. BRL-dependent augmentation of NOS activity and ROS suppression due to NE were blocked by inhibiting nNOS (L-VNIO). BRL augmented nNOS phosphorylation at Ser1412 and dephosphorylation at Ser847. Cells expressing constitutively dephosphorylated Ser1412A or phosphorylated Ser847D nNOS mutants displayed reduced nNOS activity and a lack of BRL modulation. BRL also failed to depress ROS from NE in cells with nNOS-Ser847D. Inhibiting Akt decreased BRL-induced nNOS-Ser1412 phosphorylation and NOS activation, whereas Gi/o blockade blocked BRL-regulation of both post-translational modifications, preventing enhancement of NOS activity and ROS reduction. BRL resulted in near complete dephosphorylation of Ser847 and a moderate rise in Ser1412 phosphorylation in mouse myocardium exposed to chronic pressure-overload. CONCLUSION: ß3-AR regulates myocardial NOS activity and ROS via activation of nNOS involving reciprocal changes in phosphorylation at two regulatory sites. These data identify a novel and potent anti-oxidant and anti-hypertrophic pathway due to nNOS post-translational modification that is coupled to ß3-AR receptor stimulation.


Assuntos
Antioxidantes/farmacologia , Células Musculares/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Células Cultivadas , Etanolaminas/farmacologia , Imunoprecipitação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/efeitos dos fármacos , Fosforilação , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio
14.
J Cardiovasc Transl Res ; 6(3): 436-45, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23456569

RESUMO

Obesity is associated with increased diastolic stiffness and myocardial steatosis and dysfunction. The impact of aging on the protective effects of caloric restriction (CR) is not clear. We studied 2-month (younger) and 6-7-month (older)-old ob/ob mice and age-matched C57BL/6J controls (WT). Ob/ob mice were assigned to diet ad libitum or CR for 4 weeks. We performed echocardiograms, myocardial triglyceride assays, Oil Red O staining, and measured free fatty acids, superoxide, NOS activity, ceramide levels, and Western blots. In younger mice, CR restored diastolic function, reversed myocardial steatosis, and upregulated Akt phosphorylation. None of these changes was observed in the older mice; however, CR decreased oxidative stress and normalized NOS activity in these animals. Interestingly, myocardial steatosis was not associated with increased ceramide, but CR altered the composition of ceramides. In this model of obesity, aging attenuates the benefits of CR on myocardial structure and function.


Assuntos
Restrição Calórica , Obesidade/dietoterapia , Disfunção Ventricular Esquerda/prevenção & controle , Fatores Etários , Animais , Ceramidas/metabolismo , Diástole , Modelos Animais de Doenças , Ácidos Graxos não Esterificados/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miocárdio/patologia , Óxido Nítrico Sintase/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Obesidade/fisiopatologia , Estresse Oxidativo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Triglicerídeos/metabolismo , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda , Redução de Peso
15.
Exp Gerontol ; 48(2): 128-35, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23159957

RESUMO

UNLABELLED: Cardiovascular dysfunction is a primary independent predictor of age-related morbidity and mortality. Frailty is associated with activation of inflammatory pathways and fatigue that commonly presents and progresses with age. Interleukin 10 (IL-10), the cytokine synthesis inhibitory factor, is an anti-inflammatory cytokine produced by immune and non-immune cells. Homozygous deletion of IL-10 in mice yields a phenotype that is consistent with human frailty, including age-related increases in serum inflammatory mediators, muscular weakness, higher levels of IGF-1 at midlife, and early mortality. While emerging evidence suggests a role for IL-10 in vascular protection, a clear mechanism has not yet been elucidated. METHODS: In order to evaluate the role of IL-10 in maintenance of vascular function, force tension myography was utilized to access ex-vivo endothelium dependent vasorelaxation in vessels isolated from IL-10 knockout IL-10(tm/tm) and control mice. Pulse wave velocity ((PWV), index of stiffness) of vasculature was measured using ultrasound and blood pressure was measured using the tail cuff method. Echocardiography was used to elucidated structure and functional changes in the heart. RESULTS: Mean arterial pressures were significantly higher in IL-10(tm/tm) mice as compared to C57BL6/wild type (WT) controls. PWV was increased in IL-10(tm/tm) indicating stiffer vasculature. Endothelial intact aortic rings isolated from IL-10(tm/tm) mice demonstrated impaired vasodilation at low acetylcholine doses and vasoconstriction at higher doses whereas vasorelaxation responses were preserved in rings from WT mice. Cyclo-oxygenase (COX-2)/thromboxane A2 inhibitors improved endothelial dependent vasorelaxation and reversed vasoconstriction. Left ventricular end systolic diameter, left ventricular mass, isovolumic relaxation time, fractional shortening and ejection fraction were all significantly different in the aged IL-10(tm/tm) mice compared to WT mice. CONCLUSION: Aged IL-10(tm/tm) mice have stiffer vessels and decreased vascular relaxation due to an increase in eicosanoids, specifically COX-2 activity and resultant thromboxane A2 receptor activation. Our results also suggest that aging IL-10(tm/tm) mice have an increased heart size and impaired cardiac function compared to age-matched WT mice. While further studies will be necessary to determine if this age-related phenotype develops as a result of inflammatory pathway activation or lack of IL-10, it is essential for maintaining the vascular compliance and endothelial function during the aging process. Given that a similar cardiovascular phenotype is present in frail, older adults, these findings further support the utility of the IL-10(tm/tm) mouse as a model of frailty.


Assuntos
Envelhecimento/imunologia , Aorta/imunologia , Doenças Cardiovasculares/imunologia , Endotélio Vascular/imunologia , Mediadores da Inflamação/metabolismo , Inflamação/imunologia , Interleucina-10/deficiência , Fatores Etários , Envelhecimento/genética , Animais , Aorta/efeitos dos fármacos , Aorta/fisiopatologia , Pressão Arterial , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Relação Dose-Resposta a Droga , Ecocardiografia Doppler , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Genótipo , Inflamação/genética , Inflamação/fisiopatologia , Interleucina-10/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miografia , Fenótipo , Análise de Onda de Pulso , Volume Sistólico , Tromboxano A2/antagonistas & inibidores , Tromboxano A2/metabolismo , Rigidez Vascular , Vasoconstrição , Vasoconstritores/farmacologia , Vasodilatação , Vasodilatadores/farmacologia , Função Ventricular Esquerda
16.
Isr Med Assoc J ; 14(11): 666-71, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23240370

RESUMO

BACKGROUND: Determining the prognosis of patients with heart failure is essential for patient management and clinical trial conduct. The relative value of traditional prognostic criteria remains unclear and the assessment of long-term prognosis for individual patients is problematic. OBJECTIVES: To determine the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of patients with idiopathic dilated cardiomyopathy. METHODS: We investigated the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of individual patients in a large, representative, contemporary cohort of idiopathic dilated cardiomyopathy (IDCM) patients referred to Johns Hopkins from 1997 to 2004 for evaluation of cardiomyopathy. In all patients a baseline history was taken, and physical examination, laboratory studies, echocardiogram, right heart catheterization and endomyocardial biopsy were performed. RESULTS: In 171 IDCM patients followed for a median 3.5 years, there were 50 long-term event-free survivors (LTS) (median survival 6.4 years) and 34 patients died or underwent ventricular assist device placement or transplantation within 5 years (NLTS; non-long-term survivors) (median time to event 1.83 years. Established risk factors (gender, race, presence of diabetes, serum creatinine, sodium) and the use of accepted heart failure medications (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta blockers) were similar between the two groups. Although LTS had younger age, higher ejection fraction (EF) and lower New York Heart Association (NYHA) class at presentation, the positive predictive value of an EF < 25% was 64% (95% CI 41%-79%) and that of NYHA class > 2 was 53% (95% CI 36-69%). A logistic model incorporating these three variables incorrectly classified 29% of patients. CONCLUSIONS: IDCM exhibits a highly variable natural history and standard clinical predictors have limited ability to classify IDCM patients into broad prognostic categories. These findings suggest that there are important host-environmental factors still unappreciated in the biology of IDCM.


Assuntos
Cardiomiopatia Dilatada/diagnóstico , Hemodinâmica , Miocárdio/patologia , Biópsia , Cateterismo Cardíaco , Cardiomiopatia Dilatada/sangue , Cardiomiopatia Dilatada/fisiopatologia , Creatinina/sangue , Diagnóstico Diferencial , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
17.
J Am Coll Cardiol ; 59(22): 1979-87, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22624839

RESUMO

OBJECTIVES: The aim of this study was to determine whether activation of ß3-adrenergic receptor (AR) and downstream signaling of nitric oxide synthase (NOS) isoforms protects the heart from failure and hypertrophy induced by pressure overload. BACKGROUND: ß3-AR and its downstream signaling pathways are recognized as novel modulators of heart function. Unlike ß1- and ß2-ARs, ß3-ARs are stimulated at high catecholamine concentrations and induce negative inotropic effects, serving as a "brake" to protect the heart from catecholamine overstimulation. METHODS: C57BL/6J and neuronal NOS (nNOS) knockout mice were assigned to receive transverse aortic constriction (TAC), BRL37344 (ß3 agonist, BRL 0.1 mg/kg/h), or both. RESULTS: Three weeks of BRL treatment in wild-type mice attenuated left ventricular dilation and systolic dysfunction, and partially reduced cardiac hypertrophy induced by TAC. This effect was associated with increased nitric oxide production and superoxide suppression. TAC decreased endothelial NOS (eNOS) dimerization, indicating eNOS uncoupling, which was not reversed by BRL treatment. However, nNOS protein expression was up-regulated 2-fold by BRL, and the suppressive effect of BRL on superoxide generation was abrogated by acute nNOS inhibition. Furthermore, BRL cardioprotective effects were actually detrimental in nNOS(-/-) mice. CONCLUSIONS: These results are the first to show in vivo cardioprotective effects of ß3-AR-specific agonism in pressure overload hypertrophy and heart failure, and support nNOS as the primary downstream NOS isoform in maintaining NO and reactive oxygen species balance in the failing heart.


Assuntos
Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Insuficiência Cardíaca/prevenção & controle , Hipertrofia Ventricular Esquerda/prevenção & controle , Contração Miocárdica/efeitos dos fármacos , Miocárdio/enzimologia , Óxido Nítrico Sintase Tipo I/biossíntese , Remodelação Ventricular/fisiologia , Animais , Western Blotting , Catecolaminas/sangue , Modelos Animais de Doenças , Seguimentos , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/fisiopatologia , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/patologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Remodelação Ventricular/efeitos dos fármacos
18.
J Am Coll Cardiol ; 58(25): 2683-91, 2011 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-22152956

RESUMO

OBJECTIVES: This paper examined whether nebivolol protects the heart via nitric oxide (NO) synthase and NO-dependent signaling in an in vivo model of acute myocardial infarction. BACKGROUND: Beta(3)-adrenergic receptor (AR) activation promotes endothelial nitric oxide synthase (eNOS) activity and NO bioavailability. We hypothesized that specific beta(3)-AR agonists would attenuate myocardial ischemia-reperfusion (MI/R) injury via eNOS activation and increased NO bioavailability. METHODS: Mice were subjected to 45 min of myocardial ischemia in vivo followed by 24 h of reperfusion (R). Nebivolol (500 ng/kg), CL 316243 (1 µg/kg), BRL-37344 (1 µg/kg), or vehicle (VEH) was administered at the time of R. Myocardial area-at-risk (AAR) and infarct size (INF)/AAR was measured at 24 h of R. Cardiac tissue and plasma were collected to evaluate eNOS phosphorylation, neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase expression, and nitrite and nitrosothiol levels. RESULTS: Nebivolol (500 ng/kg) reduced INF/AAR by 37% (p < 0.001 vs. VEH) and serum troponin-I levels from 41 ± 4 ng/ml to 25 ± 4 ng/ml (p < 0.05 vs. VEH). CL 316243 and BRL-37344 reduced INF by 39% and 42%, respectively (p < 0.001 vs. VEH). Nebivolol and CL 316243 increased eNOS phosphorylation at Ser-1177 (p < 0.05 vs. VEH) and increased nitrite and total nitrosylated protein levels. Nebivolol and CL 316243 significantly increased myocardial nNOS expression. Nebivolol failed to reduce INF after MI/R in beta(3)-AR (-/-), eNOS(-/-), and in nNOS(-/-) mice. CONCLUSIONS: Our results indicate that beta(3)-AR agonists protect against MI/R injury. Furthermore, the cardioprotective effects of beta(3)-AR agonists are mediated by rapid eNOS and nNOS activation and increased NO bioavailability.


Assuntos
Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Benzopiranos/farmacologia , Etanolaminas/farmacologia , Traumatismo por Reperfusão Miocárdica/enzimologia , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Receptores Adrenérgicos beta 3/efeitos dos fármacos , Animais , Disponibilidade Biológica , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nebivolol
19.
Circ Res ; 108(12): 1448-58, 2011 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-21527738

RESUMO

RATIONALE: Exercise training confers sustainable protection against ischemia-reperfusion injury in animal models and has been associated with improved survival following a heart attack in humans. It is still unclear how exercise protects the heart, but it is apparent that endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) play a role. OBJECTIVE: To determine the role of ß(3)-adrenergic receptors (ß(3)-ARs), eNOS activation, and NO metabolites (nitrite and nitrosothiols) in the sustained cardioprotective effects of exercise. METHODS AND RESULTS: Here we show that voluntary exercise reduces myocardial injury in mice following a 4-week training period and that these protective effects can be sustained for at least 1 week following the cessation of the training. The sustained cardioprotective effects of exercise are mediated by alterations in the phosphorylation status of eNOS (increase in serine 1177 and decrease in threonine 495), leading to an increase in NO generation and storage of NO metabolites (nitrite and nitrosothiols) in the heart. Further evidence revealed that the alterations in eNOS phosphorylation status and NO generation were mediated by ß(3)-AR stimulation and that in response to exercise a deficiency of ß(3)-ARs leads to an exacerbation of myocardial infarction following ischemia-reperfusion injury. CONCLUSIONS: Our findings clearly demonstrate that exercise protects the heart against myocardial ischemia-reperfusion injury by stimulation of ß(3)-ARs and increased cardiac storage of nitric oxide metabolites (ie, nitrite and nitrosothiols).


Assuntos
Exercício Físico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Compostos Nitrosos/metabolismo , Condicionamento Físico Animal , Receptores Adrenérgicos beta 3/metabolismo , Adolescente , Adulto , Animais , Ativação Enzimática , Humanos , Masculino , Camundongos , Camundongos Knockout , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Óxido Nítrico/genética , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Receptores Adrenérgicos beta 3/genética , Fatores de Tempo
20.
Physiol Genomics ; 43(12): 726-38, 2011 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21427359

RESUMO

OBJECTIVE: Evidence supports an antilipotoxic role for leptin in preventing inappropriate peripheral tissue lipid deposition. Obese, leptin-deficient mice develop left ventricular (LV) hypertrophy and myocardial steatosis with increased apoptosis and decreased longevity. Here we investigated the cardiac effects of caloric restriction versus leptin repletion in obese leptin-deficient (ob/ob) mice. METHODS: Echocardiography was performed on 7 mo old C57BL/6 wild-type mice (WT) and ob/ob mice fed ad libitum, leptin-repleted (LR-ob/ob), or calorie-restricted (CR-ob/ob) for 4 wk. Ventricular tissue was examined by electron microscopy (EM), triglyceride (TAG) content, oil red O staining, mitochondrial coupling assay, and microarray expression profiling. RESULTS: LR and CR-ob/ob mice showed decreased body and heart weight, and LV wall thickness compared with ad libitum ob/ob mice. LV fractional shortening was decreased in ad libitum ob/ob mice, but restored to WT in LR and CR groups. However, myocardial lipid content by EM and TAG analysis revealed persistent cardiac steatosis in the CR-ob/ob group. Although CR restored mitochondrial coupling to WT levels, PPARα was suppressed and genes associated with oxidative stress and cell death were upregulated in CR-ob/ob animals. In contrast, LR eliminated cardiac steatosis, normalized mitochondrial coupling, and restored PGC1α and PPARα expression, while inducing core genes involved in glycerolipid/free fatty acid (GL/FFA) cycling, a thermogenic pathway that can reduce intracellular lipids. CONCLUSIONS: Thus, CR in the absence of leptin fails to normalize cardiac steatosis. GL/FFA cycling may be, at least in part, leptin-dependent and a key pathway that protects the heart from lipid accumulation.


Assuntos
Restrição Calórica/métodos , Hipertrofia Ventricular Esquerda/patologia , Leptina/deficiência , Lipídeos/análise , Miocárdio/química , PPAR alfa/metabolismo , Análise de Variância , Animais , Apoptose/genética , Peso Corporal , Ecocardiografia , Perfilação da Expressão Gênica , Hipertrofia Ventricular Esquerda/etiologia , Leptina/administração & dosagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Análise em Microsséries , Microscopia Eletrônica , Miocárdio/patologia , Estresse Oxidativo/genética
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