Sex-Related Effects of Prenatal Stress on Region-Specific Expression of Monoamine Oxidase A and β Adrenergic Receptors in Rat Hearts / Efeitos Sexo-Específicos de Estresse Pré-Natal na Expressão Região-Específica de Monoamina Oxidase A e Receptores Adrenérgicos Β no Coração de Ratos

Abstract Background: Prenatal stress may increase risk of developing cardiovascular disorders in adulthood. The cardiotoxic effects of catecholamines are mediated via prolonged adrenergic receptor stimulation and increased oxidative stress upon their degradation by monoamine oxidase A (MAO-A). Objectives: We investigated long-term effects of prenatal stress on β (1, 2, 3) adrenergic receptors and MAO-A gene expression in the hearts of adult rat offspring. Methods: Pregnant rats were exposed to unpredictable mild stress during the third week of gestation. RNA was isolated from left ventricular apex and base of adult offspring. Quantitative PCR was used to measure gene expression in collected ventricular tissue samples. The level of significance was set to p < 0.05. Results: β3 adrenergic receptor mRNA was undetectable in rat left ventricle. β1 adrenergic receptor was the predominantly expressed subtype at the apical and basal left ventricular myocardium in the control females. Male offspring from unstressed mothers displayed higher apical cardiac β1 than β2 adrenergic receptor mRNA levels. However, β1 and β2 adrenergic receptor mRNAs were similarly expressed at the ventricular basal myocardium in males. Unlike males, prenatally stressed females exhibited decreased β1 adrenergic receptor mRNA expression at the apical myocardium. Prenatal stress did not affect cardiac MAO-A gene expression. Conclusions: Collectively, our results show that prenatal stress may have exerted region- and sex-specific β1 and β2 adrenergic receptor expression patterns within the left ventricle.

Resumo Fundamento: Estresse pré-natal pode aumentar os riscos de desenvolver doenças cardiovasculares na idade adulta. Os efeitos cardiotóxicos de catecolaminas são mediados pela estimulação prolongada dos receptores adrenérgicos e pelo aumento do estresse oxidativo após sua degradação pela monoamina oxidase A (MAO-A). Objetivos: Investigamos os efeitos a longo prazo de estresse pré-natal nos receptores β (1, 2, 3) adrenérgicos e na expressão do gene MAO-A nos corações da prole adulta de ratos. Método: Ratas prenhes foram expostas a estresse crônico moderado imprevisível durante a terceira semana de gestação. O RNA foi isolado do ápice e da base do ventrículo esquerdo da prole adulta. Utilizou-se PCR quantitativa em tempo real para medir a expressão gênica nas amostras de tecido ventricular coletadas. O nível de significância foi estabelecido em p < 0,05. Resultados: Foi indetectável o mRNA do receptor adrenérgico β3 no ventrículo esquerdo dos ratos. O receptor adrenérgico β1 foi o subtipo mais expresso no miocárdio ventricular esquerdo apical e basal nas fêmeas controle. A prole masculina das mães não estressadas apresentou níveis cardíacos apicais de mRNA do receptor adrenérgico β1 mais altos do que os de β2. Porém, mRNAs dos receptores adrenérgicos β1 e β2 foram expressos de forma semelhante no miocárdio basal ventricular na prole masculina em geral. Ao contrário da prole masculina, a prole feminina exposta ao estresse pré-natal exibiu uma expressão diminuída do mRNA do receptor adrenérgico β1 no miocárdio apical. O estresse pré-natal não afetou a expressão gênica de MAO-A cardíaca. Conclusões: Coletivamente, nossos resultados mostram que estresse pré-natal pode ter exercido padrões de expressão região- e sexo-específica dos receptores adrenérgicos β1 e β2 no ventrículo esquerdo.

Moderate Continuous Aerobic Exercise Training Improves Cardiomyocyte Contractility in Β1 Adrenergic Receptor Knockout Mice / Treinamento Aeróbico Contínuo de Intensidade Moderada Melhora a Contratilidade do Cardiomiócito em Camundongos com Nocaute para o Receptor B1-Adrenérgico

Abstract Background: The lack of cardiac β1-adrenergic receptors (β1-AR) negatively affects the regulation of both cardiac inotropy and lusitropy, leading, in the long term, to heart failure (HF). Moderate-intensity aerobic exercise (MCAE) is recommended as an adjunctive therapy for patients with HF. Objective: We tested the effects of MCAE on the contractile properties of left ventricular (LV) myocytes from β1 adrenergic receptor knockout (β1ARKO) mice. Methods: Four- to five-month-old male wild type (WT) and β1ARKO mice were divided into groups: WT control (WTc) and trained (WTt); and β1ARKO control (β1ARKOc) and trained (β1ARKOt). Animals from trained groups were submitted to a MCAE regimen (60 min/day; 60% of maximal speed, 5 days/week) on a treadmill, for 8 weeks. P ≤ 0.05 was considered significant in all comparisons. Results: The β1ARKO and exercised mice exhibited a higher (p < 0.05) running capacity than WT and sedentary ones, respectively. The β1ARKO mice showed higher body (BW), heart (HW) and left ventricle (LVW) weights, as well as the HW/BW and LVW/BW than WT mice. However, the MCAE did not affect these parameters. Left ventricular myocytes from β1ARKO mice showed increased (p < 0.05) amplitude and velocities of contraction and relaxation than those from WT. In addition, MCAE increased (p < 0.05) amplitude and velocities of contraction and relaxation in β1ARKO mice. Conclusion: MCAE improves myocyte contractility in the left ventricle of β1ARKO mice. This is evidence to support the therapeutic value of this type of exercise training in the treatment of heart diseases involving β1-AR desensitization or reduction.

Resumo Fundamento: A falta de receptores β1-adrenérgicos (β1-AR) cardíacos afeta negativamente a regulação de inotropismo e lusitropismo cardíacos, levando, no longo prazo, a insuficiência cardíaca (IC). Recomenda-se exercício aeróbico contínuo de intensidade moderada (EACM) como adjuvante no tratamento de pacientes com IC. Objetivo: Testar os efeitos do EACM nas propriedades contráteis de miócitos do ventrículo esquerdo (VE) de camundongos com nocaute para o receptor β1-adrenérgico (β1ARKO). Método: Camundongos machos com 4 a 5 meses de idade, wild-type (WT) e β1ARKO foram divididos em grupos: WT controle (WTc) e treinado (WTt); e β1ARKO controle (β1ARKOc) e treinado (β1ARKOt). Os grupos treinados foram submetidos a regime de EACM (60 min/dia; 60% da velocidade máxima, 5 dias/semana) em esteira rolante, por 8 semanas. Adotou-se P ≤ 0,05 como nível de significância em todas as comparações. Resultados: Os animais β1ARKO (β1ARKOc + β1ARKOt) correram uma distância maior do que os animais WT (WTc + WTt) (p < 0,05). Os camundongos β1ARKO apresentaram maiores pesos corporal (PC), do coração (PCo) e do ventrículo esquerdo (PVE), assim como PCo/PC e PVE/PC do que os camundongos WT. Entretanto, o EACM não afetou tais parâmetros. Os miócitos do VE de camundongos β1ARKO apresentaram maiores (p < 0,05) amplitude e velocidades de contração e relaxamento do que os dos camundongos WT. Além disso, o EACM aumentou (p < 0,05) a amplitude e as velocidades de contração e relaxamento nos camundongos β1ARKO. Conclusão: O EACM melhora a contratilidade do miócito do VE de camundongos β1ARKO. Tal achado confirma o valor terapêutico desse tipo de treinamento físico para o tratamento de doenças cardíacas envolvendo dessensibilização ou redução de β1-AR.

Carvedilol atenua o estresse oxidativo na cardiopatia chagásica crônica / Carvedilol attenuates oxidative stress in chronic chagasic cardiomyopathy / Carvedilol atenúa el estrés oxidativo en la cardiopatía chagásica crónica

FUNDAMENTO: Há cada vez mais evidências sugerindo que doença de Chagas envolve dano oxidativo e contribui para a progressão da doença cardíaca. OBJETIVO: Avaliar o efeito do carvedilol sobre marcadores de estresse oxidativo na doença de Chagas crônica. MÉTODOS: A população de estudo incluiu 42 pacientes com cardiopatia chagásica e os biomarcadores de estresse oxidativo foram medidos antes e após um período de seis meses de tratamento com carvedilol (37,5 mg/dia). Os pacientes foram considerados de acordo com a classificação de Los Andes, e a atividade da superóxido dismutase, catalase, glutationa peroxidase, S-transferase e redutase, mieloperoxidase e adenosina deaminase; e os níveis de glutationa reduzida, de espécies reativas do ácido tiobarbitúrico, proteína carbonil, vitamina E e óxido nítrico foram medidos no sangue. RESULTADOS: Após o tratamento com carvedilol, todos os grupos apresentaram reduções significativas nos níveis de proteína carbonil e glutationa reduzida, enquanto os níveis de óxido nítrico e atividade da adenosina aumentaram significativamente somente no grupo IA. Além disso, a maioria das enzimas antioxidantes apresentou diminuição de suas atividades, nos grupos IA e IB. CONCLUSÃO: Os dados sugerem que o tratamento com carvedilol foi eficaz na atenuação do dano oxidativo, um efeito que pode ser particularmente importante em doença de Chagas crônica com cardiopatia.

BACKGROUND: There is increasing evidence suggesting that Chagas disease involves oxidative damage and contributes to heart disease progression. OBJECTIVE: To evaluate the effect of carvedilol on oxidative stress markers in chronic Chagas disease. METHODS: The study population included 42 patients with Chagas cardiomyopathy and oxidative stress biomarkers were measured before and after a period of six months of treatment with carvedilol (37.5 mg/day). Patients were considered according to the Los Andes classification and the activity of superoxide dismutase, catalase, glutathione peroxidase, S-transferase and reductase, myeloperoxidase and adenosine deaminase; levels of reduced glutathione, thiobarbituric acid reactive species, carbonyl protein, vitamin E and nitric oxide were measured in blood. RESULTS: After treatment with carvedilol, all groups showed significant reductions in levels of carbonyl protein and reduced glutathione, whereas the levels of nitric oxide and adenosine activity increased significantly only in group IA. Moreover, most of the antioxidant enzymes showed decrease in activity in groups IA and IB. CONCLUSION: The data suggest that treatment with carvedilol was effective in attenuating oxidative damage, an effect that may be particularly important in patients with chronic Chagas' disease cardiomyopathy.

FUNDAMENTO: Hay cada vez más evidencias sugiriendo que la enfermedad de Chagas envuelve daño oxidativo y contribuye a la progresión de la enfermedad cardíaca. OBJETIVO: Evaluar el efecto del carvedilol sobre marcadores de estrés oxidativo en la enfermedad de Chagas crónica. MÉTODOS: La población de estudio incluyó 42 pacientes con cardiopatía chagásica y los biomarcadores de estrés oxidativo fueron medidos antes y después de un período de seis meses de tratamiento con carvedilol (37,5 mg/día). Los pacientes fueron considerados de acuerdo con la clasificación de Los Andes, y la actividad de la superóxido dismutasa, catalasa, glutatión peroxidasa, S-transferasa y reductasa, mieloperoxidasa y adenosina deaminasa; y los niveles de glutatión reducida, de especies reactivas del ácido tiobarbitúrico, proteína carbonil, vitamina E y óxido nítrico fueron medidos en la sangre. RESULTADOS: Después del tratamiento con carvedilol, todos los grupos presentaron reducciones significativas en los niveles de proteína carbonil y glutatión reducida, mientras que los niveles de óxido nítrico y actividad de la adenosina aumentaron significativamente solamente en el grupo IA. Además de eso, la mayoría de las enzimas antioxidantes presentó disminución de sus actividades, en los grupos IA e IB. CONCLUSIONES: Los datos sugieren que el tratamiento con carvedilol fue eficaz en la atenuación del daño oxidativo, un efecto que puede ser particularmente importante en enfermedad de Chagas crónica con cardiopatía.

Effects of substance P pretreatment on norepinephrine-induced β1-adrenoreceptor expression in cultured rat cardiomyocytes / 中华麻醉学杂志

Objective To investigate the effects of substance P (SP) pretreatment on the expression of β1-adrenoreceptor(β1-R) induced by norepinephrine (NE) in cultured neonatal rat cardiomyecytes.Methods The cardiomyocytes obtained from 1-3 day old SD rats were cultured for 72 h.The experiment was performed in 2 parts.In part 1 the cells were seeded in 15 well plate and randomly divided into 5 groups (n=3 wells each):control group (C1)and 4 NE groups were exposed to NE 10-9, 10-8,10-7,10-6 mol/L respectively (NE1,2,3,4).In part Ⅱ the.cells were seeded in 12 well plate and randomly divided into 4 groups (n=3 wells each): group I control (C2): group II NE 10-7 tool/L; group Ⅲ (SN)was pretreated with SP 10-6 mol/L 30 minbefore NE 10-7 mol/L and group IV (NSN)was treated with NK-1 receptor antagonist (NK-1 tachykinin receptor antagonist,S3144) 30 min before SP pretreatment.After exposure to NE for 3 h the expression of β1-R in the rat cardiomyecytes was detected using flow cytometry.Results In part Ⅰ the expression of β1-R was significantly higher in group NE1-3 than in control group (C1),with the highest expression in group NF3.In part Ⅱ the expression of β1-R was significantly higher in group Ⅱ (NE) than in control group (C2) while lower in group Ⅲ (SN) than in control group Ⅱ.(NE).There was no significant difference in the expression of β1-R between group Ⅰ (C2) and group Ⅲ and Ⅳ (NSN).Conclusion Substance P pretreatment can inhibit the up-regulation of β1-R expression in cultured rat cardiomyocytes induced by norepinephrine through activating NK-1 receptor.

Study on the roles of autoantibodies against ?1 adrenoceptor and M2 cholinergic receptor in patients with chronic renal insufficiency / 中国医师杂志

Objective To explore the roles of autoantibodies against ?1 adrenoceptor(?1-receptor)and M2 cholinergic receptor(M2-receptor)in patients with chronic renal insufficiency.Methods The epitopes of the second extracellular loop of ?1 receptor and M2 receptor were synthesized and used respectively to detect the sera autoantibodies against ?1 receptor and M2 receptor by enzyme linked immunosorbent assay(ELISA) in 76 patients with chronic renal insufficiency,60 cases with hypertension and 40 healthy controls.Results In patients with chronic renal insufficiency,the positive rates of the autoantibodies against ?1-receptor and M2-receptor were 56.7% and 38.1% respectively,which were much higher than those of patients with hypertension(18.3% and 11.7%) and higher than those of healthy controls(17.5% and 15.0%)(all P

Analysis of the autoantibodies against ?_1 and ?_1-adrenergic receptor in patients of hypertension with renal failure / 中国医师杂志

Objective To explore the role of the autoantibodies against ?_1 and ?_1-adrenergic receptor(?_1-receptor)in the development of hypertension with renal failure.Methods The epitopes of the second extracellular loop of ?_1-receptor(197-222) and ?_1-receptor(192-218) were synthesized and used respectively to screen sera autoantibodies in patients with hypertension and renal failure(n=61),hypertension without renal failure(n=60) and healthy blood donors(n=40,control) by ELISA.Results The positive rates of the autoantibodies against ?_1-receptor(62.3%)and ?_1 receptor(50.8%) in patients with hypertension with renal failure were higher than those of patients with hypertension without renal failure(13.3% and10.0%)(P