Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nutrients ; 10(12)2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30513887

RESUMO

It has been well established that moderate alcohol consumption inversely correlates with cardiovascular morbidity and mortality, whereas binge alcohol drinking increases cardiovascular disease risk. The aim of this study was to assess in vivo the impact of different drinking patterns on reverse cholesterol transport (RCT); the atheroprotective process leading to the removal of excess cholesterol from the body. RCT was measured with a standardized, radioisotope-based technique in three groups of atherosclerosis-prone apolipoprotein E knock out mice: Placebo group, receiving water, which would mimic the abstainers; moderate group, receiving 0.8 g/kg alcohol/day for 28 days, which would mimic a moderate intake; binge group, receiving 0.8 g/kg alcohol/day for 5 days/week, followed by the administration of 2.8 g/kg alcohol/day for 2 days/week, which would mimic a heavy intake in a short period. Mice in the binge drinking group displayed an increase in total cholesterol, high density lipoprotein cholesterol (HDL-c) and non-HDL-c (all p < 0.0001 vs. placebo), and a significantly reduced elimination of fecal cholesterol. The moderate consumption did not lead to any changes in circulating lipids, but slightly improved cholesterol mobilization along the RCT pathway. Overall, our data confirm the importance of considering not only the total amount, but also the different consumption patterns to define the impact of alcohol on cardiovascular risk.


Assuntos
Consumo de Bebidas Alcoólicas , Colesterol/metabolismo , Etanol/administração & dosagem , Etanol/efeitos adversos , Animais , Apolipoproteínas E/metabolismo , Transporte Biológico/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
2.
J Hypertens ; 25(8): 1719-30, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17620971

RESUMO

OBJECTIVE AND METHODS: Left ventricular hypertrophy in human and experimental hypertension is not always associated with pressure overload but seems to precede an increase in blood pressure. In this study, performed in male 5-week-old prehypertensive spontaneously hypertensive rats (SHR; n = 65) and age-matched Wistar-Kyoto rats (n = 56), the relationship between myocardial structure and activation of the adrenergic and nitric oxide systems was evaluated. RESULTS: Body weight, blood pressure and heart rate were similar in both groups. A higher left ventricle/body weight ratio was found in SHR, as a result of greater mononuclear (+47%) and binuclear (+43%) myocyte volumes, without changes in interstitial collagen. Both adrenergic and nitric oxide pathways were activated in SHR, as expressed by higher myocardial norepinephrine content, tyrosine hydroxylase activity, myocardial nitric oxide synthase 3 expression and protein nitration, indicating greater peroxynitrite (ONOO) generation from nitric oxide and superoxide. No difference was measured in nitric oxide synthase 1 expression, whereas nitric oxide synthase 2 was undetectable. A positive correlation between myocardial tyrosine hydroxylase activity and protein nitration was observed in SHR (r = 0.328; P < 0.01). Early treatment with a superoxide dismutase mimetic, 4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl, from the third to the fifth week of age, reduced ONOO generation, protein nitration and sympathetic activation in SHR without changes in myocardial structure. CONCLUSION: In prehypertensive SHR, left ventricular hypertrophy is associated with adrenergic and nitrosative imbalance. Early superoxide dismutase mimetic treatment in SHR effectively reduces higher myocardial ONOO generation, sympathetic activation, and heart rate without affecting the development of myocardial hypertrophy.


Assuntos
Cardiomegalia/fisiopatologia , Hipertensão/fisiopatologia , Nitrosação , Receptores Adrenérgicos/metabolismo , Animais , Cardiomegalia/metabolismo , Catecolaminas/metabolismo , Hipertensão/metabolismo , Imuno-Histoquímica , Miocárdio/enzimologia , Miocárdio/metabolismo , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Tirosina 3-Mono-Oxigenase/metabolismo
3.
J Clin Endocrinol Metab ; 90(5): 2888-97, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15741261

RESUMO

Advanced heart failure is characterized by increased activation of the renin-angiotensin system and the development of cachexia. Angiotensin II (Ang II) has been proposed as a lipid metabolism regulator. The effects of exogenous Ang II (osmotic minipump, 525 ng/kg/min for 12 d) on interstitial sc glycerol and norepinephrine levels, indexes of lipolysis, and sympathetic activation, respectively, were measured in Sprague Dawley rats by consecutive microdialysis performed in vivo in white adipose tissue. Higher sustained interstitial glycerol and norepinephrine levels were found after 7 and 12 d of Ang II infusion. Triglyceride to DNA content ratio and adipocyte diameter were reduced in sc and visceral (retroperitoneal and epididymal) fat tissues of Ang II-infused rats, whose body weight was lower and blood pressure higher. Losartan, an Ang II receptor 1 blocker, and carvedilol, an alpha1-nonselective-beta1,2,3-adrenergic blocker, but not doxazosin, an alpha1-selective-adrenergic blocker, lowered glycerol and norepinephrine levels, preventing lipolysis and weight loss. Our results indicate that Ang II stimulates lipolysis in sc and visceral adipocytes by sympathetic activation and beta-adrenergic-receptor stimulation. Nonselective-beta-adrenergic and Ang II-receptor1 blockade markedly attenuated the rise of norepinephrine, preventing catabolic effects. The metabolic benefits of carvedilol and losartan, in addition to recognized protective cardiovascular effects, may be relevant in cachectic patients with advanced heart failure.


Assuntos
Tecido Adiposo/metabolismo , Angiotensina II/farmacologia , Carbazóis/farmacologia , Lipólise/efeitos dos fármacos , Losartan/farmacologia , Propanolaminas/farmacologia , Sistema Nervoso Simpático/efeitos dos fármacos , Adipócitos/patologia , Angiotensina II/sangue , Animais , Pressão Sanguínea , Peso Corporal , Carvedilol , Glicerol/metabolismo , Frequência Cardíaca , Masculino , Norepinefrina/metabolismo , Ratos , Ratos Sprague-Dawley , Esterol Esterase/metabolismo , Sistema Nervoso Simpático/fisiologia , Triglicerídeos/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
4.
Toxicol Lett ; 134(1-3): 219-25, 2002 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-12191881

RESUMO

This study was aimed at evaluating whether controlled short-term exposure to ozone (O(3)) induces changes in biomarkers of lung inflammation and oxidative stress in exhaled breath condensate (EBC) and blood of healthy subjects. Twenty-two volunteers were exposed to 0.1 ppm of O(3) for 2 h while performing moderate intermittent exercise. EBC and blood were collected before, immediately after and 18 h after exposure. Changes in biomarkers were measured both in EBC and blood, without significant alterations of lung function tests. Changes in EBC, but not in blood, were mainly accounted for by a subgroup of 'susceptible' individuals bearing the wild genotype for NAD(P)H:quinone oxidoreductase (NQO1) and the null genotype for glutathione-S-transferase M1 (GSTM1). Thus, a single 2-h exposure to 0.1 ppm of O(3) induces changes in biomarkers of inflammation and oxidative stress. Polymorphic NQO1 and GSTM1 act as modifier of the lung response to O(3).


Assuntos
Monitoramento Ambiental/métodos , Estresse Oxidativo/efeitos dos fármacos , Ozônio/administração & dosagem , Adulto , Biomarcadores/sangue , Testes Respiratórios , Teste de Esforço , Feminino , Predisposição Genética para Doença , Genótipo , Glutationa Transferase/genética , Humanos , Exposição por Inalação , Pulmão/efeitos dos fármacos , Pulmão/fisiologia , Masculino , Estresse Oxidativo/fisiologia , Quinona Redutases/genética , Espirometria
5.
Hypertension ; 39(2 Pt 2): 656-61, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11882626

RESUMO

The activation of the sympathetic nervous system is a common feature of arterial hypertension and other cardiovascular diseases. This activation might be dependent on an altered baroreflex control of vascular resistance of which the inhibitory response on sympathetic activity appears impaired. The aim of the study was to monitor during the natural course of arterial hypertension in spontaneously hypertensive (SHR) and age-matched Wistar Kyoto (WKY) rats (5, 16, 30, and 54 weeks of age) the peripheral sympathetic activity expressed as interstitial norepinephrine (NE) release and as tyrosine hydroxylase (TH) activity, the rate-limiting enzyme of NE synthesis, in the differently baroreflex-controlled subcutaneous adipose tissues and skeletal muscles. Blood pressure and plasma NE in SHR were similar to WKY at 5 weeks of age but increased at all other ages. Body weight was similar in both 5-week-old rats but reduced in SHR at all other ages. The interstitial NE levels were greater in both SHR tissues at all ages as compared with WKY. In adipose tissue of SHR, TH activity was higher at all ages as compared with WKY, whereas TH activity in skeletal muscle was higher only after the development of hypertension. These data show that in both SHR tissues, an increase of interstitial NE release is always present during its lifespan. This suggests that increased sympathetic activation in the SHR model is not specific to baroreflex-controlled tissues such as skeletal muscle but involves also subcutaneous adipose tissue, the sympathetic efferents of which are independent from baroreflexes.


Assuntos
Tecido Adiposo/fisiopatologia , Hipertensão/fisiopatologia , Músculo Esquelético/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Tecido Adiposo/enzimologia , Tecido Adiposo/metabolismo , Animais , Pressão Sanguínea , Peso Corporal , Frequência Cardíaca , Hipertensão/metabolismo , Masculino , Microdiálise , Músculo Esquelético/enzimologia , Norepinefrina/sangue , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Tirosina 3-Mono-Oxigenase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA