Leonardo Zornoff - Academia.edu (original) (raw)
Papers by Leonardo Zornoff
Arquivos Brasileiros De Cardiologia, Jun 1, 2009
![Research paper thumbnail of [Cigarette smoke exposure intensifies ventricular remodeling process following myocardial infarction]](https://attachments.academia-assets.com/102061166/thumbnails/1.jpg)
](Arquivos Brasileiros de Cardiologia
To evaluate the role of cigarette smoke exposure (CSE) on ventricular remodeling following acute ... more To evaluate the role of cigarette smoke exposure (CSE) on ventricular remodeling following acute myocardial infarction (AMI). METHODS Rats were submitted to myocardial infarction and divided into two groups: C (control, n = 31) and F (CSE: 40 cigarettes/day, n = 22). After 6 months, the survivors were submitted to echocardiogram, functional study with isolated heart, and morphometric analysis. For comparison purposes, we used the t test (mean ± standard deviation) or the Mann-Whitney test (with median and 25 th and 75 th percentiles). RESULTS The CSE animals tended to have larger diastolic (C = 1.5 ± 0.4 mm 2 , F = 1.9 ± 0.4 mm 2 ; p = 0.08) and systolic (C = 1.05 ± 0.3 mm 2 , F = 1.32 ± 0.4 mm 2 ; p = 0.08) left ventricular(LV) areas. The systolic function of the LV, assessed according to the fractional area change, tended to be impaired in CSE animals (C = 31.9 ± 9.3%, F = 25.5 ± 7.6%; p = 0.08). The-dp/dt values for CSE animals were statistically lower (C = 1474 ± 397 mmHg, F = 916 ± 261 mmHg; p = 0.02) than for control animals. The CSE animals presented higher right ventricle (RV) weight adjusted for body weight (C = 0.8 ± 0.3 mg/g, F = 1.3 ± 0.4 mg/g; p = 0.01), higher content of water in lungs (C = 4.8 (4.3-4.8)%, F = 5.4 (5.1-5.5); p = 0.03), and larger LV myocyte cross-sectional areas (C = 239.8 ± 5.8 µm 2 , F = 253.9 ± 7.9 µm 2 ; p = 0.01). CONCLUSION Cigarette smoke exposure intensifies ventricular remodeling following acute myocardial infarction.
Medical science monitor : international medical journal of experimental and clinical research, 2010
To investigate the effect of lisinopril on cardiac remodeling induced by smoking. Rats were alloc... more To investigate the effect of lisinopril on cardiac remodeling induced by smoking. Rats were allocated into 3 groups: group CON (n=8): control; group CSE (n=8): cigarette smoke exposure; group CSE-LIS (n=8): exposed to tobacco smoke and treated with lisinopril. After 2 months, the tail systolic pressure was lower in CSE-LIS (CON=116 +/-27 mm Hg, CSE=126+/-16, CSE-LIS=89+/-12; P<.001). CSE animals showed higher left ventricular systolic diameter (CON=8.25+/-2.16 mm/kg, CSE=11.5+/-1.3, CSE-LIS=9.27+/-2.00; P=.009) and myocyte cross-sectional area (CON=245+/-8 microm2, CSE=260+/-17, CSE-LIS=238+/-12; P=.01) than CON and CSE-LIS. The ejection fraction (CON =0.91+/-0.02, CSE=0.86+/-0.02, CSE-LIS=0.92+/-0.03; P=.002) and fractional shortening (CON=55.7+/-4.41%, CSE=48.7+/-3.43, CSE-LI=58.2+/-7.63; P=.006) were lower in CSE group than CON and CSE-LIS. CSE and CSE-LIS animals showed higher collagen amounts (CON=3.49+/-0.95%, CSE= 5.01+/-1.58, CSE-LIS=5.27+/-0.62; P=.009) than CON. CON gro...
Acta cardiologica, 2011
Our objective was to test the hypothesis that retinoic acid supplementation could attenuate ventr... more Our objective was to test the hypothesis that retinoic acid supplementation could attenuate ventricular remodelling induced by tobacco smoke exposure in rats. Wistar rats were allocated into three groups: control (C, n = 8); exposed to tobacco smoke (ETS, n = 9); exposed to tobacco smoke and all-trans-retinoic acid (ETS-RA, n = 9). After two months, cardiac function and geometry were assessed by echocardiography, and geometry changes were confirmed by morphometric analysis. Data are expressed as mean +/- SD or medians (including the lower quartile and upper quartile). ETS showed higher normalized left ventricular diastolic diameters than groups C and ETS-RA (C = 18.4 +/- 3.57 mm/kg, ETS = 23.0 +/- 1.8, ETS-RA = 19.5 +/- 0.99; P <0.05) and systolic diameters (C = 8.25 +/- 2.16 mm/kg, ETS = 11.5 +/- 1.31, ETS-RA = 8.25 +/- 0.71 mm/kg; P < 0.05). ETS showed reduced ejection fraction (C= 91 +/- 2.0, ETS = 87 +/- 3.0, ETS-RA = 92 +/- 3.0; P < 0.05) and fractional shortening (C =...
The Journal of nutrition, 2005
The objective of this study was to evaluate the role of retinoic acid in experimental postinfarct... more The objective of this study was to evaluate the role of retinoic acid in experimental postinfarction myocardial remodeling. Wistar rats were subjected to myocardial infarction (MI) and treated with retinoic acid (RA), 0.3 mg/(kg x d) (MI-RA, n = 29), or fed a control diet (MI, n = 34). After 6 mo, the surviving rats (MI-RA = 18 and MI = 22) underwent echocardiograms, and isolated hearts were tested for function in vitro. The cross-sectional area of the myocyte (CSA) and interstitial collagen fraction (IC) were measured in a cross section of the heart stained by hematoxylin-eosin and picrosirius red, respectively. The CSA was smaller in the MI-RA group [229 (220,234) microm2] [medians (lower quartile, upper quartile)] than in the MI group [238 (232,241) microm2] (P = 0.01) and IC was smaller in the MI-RA group [2.4 (1.7, 3.1)%] than in the MI group [3.5 (2.6, 3.9)%] (P = 0.05). The infarct size did not differ between the groups [MI = 44.6 (40.8, 48.4)%, MI-RA = 45 (38.6, 47.2)%]. Max...
The Journal of nutrition, 2005
The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in ... more The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in rats that were or were not supplemented with dietary beta-carotene (BC), on ventricular remodeling and survival after myocardial infarction (MI). Rats (n = 189) were allocated to 4 groups: the control group, n = 45; group BC administered 500 mg/kg diet, n = 49, BC supplemented rats; group ETS, n = 55, rats exposed to tobacco smoke; and group BC+ETS, n = 40. Wistar rats weighing 100 g were administered one of the treatments until they weighed 200 to 250 g (approximately 5 wk). The ETS rats were exposed to cigarette smoke for 30 min 4 times/d, in a chamber connected to a smoking device. After reaching a weight of 200-250 g, rats were subjected to experimental MI (coronary artery occlusion) and mortality rates were determined over the next 105 d. In addition, echocardiographic, isolated heart, morphometrical, and biochemical studies were performed. Mortality data were tested using Kaplan-Me...
Arquivos Brasileiros de Cardiologia, 2014
Fundamento: Os efeitos da terapêutica moderna na recuperação funcional após o infarto agudo do mi... more Fundamento: Os efeitos da terapêutica moderna na recuperação funcional após o infarto agudo do miocárdio não são conhecidos. Objetivos: Avaliar os fatores preditores da recuperação funcional sistólica após infarto agudo do miocárdio de parede anterior em pacientes submetidos à terapia moderna (reperfusão, antiagregação plaquetária agressiva, inibidores da enzima conversora da angiotensina e betabloqueadores). Métodos: Foram incluídos 94 pacientes consecutivos com infarto agudo do miocárdio com supradesnivelamento do segmento ST. Ecocardiogramas foram realizados na fase intra-hospitalar e após 6 meses. Disfunção sistólica foi definida pela presença de fração de ejeção de valor < 50%. Resultados: No ecocardiograma inicial, 64% dos pacientes apresentaram disfunção sistólica. Os pacientes com disfunção ventricular apresentaram tamanhos maiores de infarto, avaliados pelas enzimas creatinofosfoquinase total e isoenzima MB, que os pacientes sem disfunção. Adicionalmente, 24,5% dos pacientes inicialmente com disfunção sistólica apresentaram recuperação no período de 6 meses após o infarto agudo do miocárdio. Os pacientes que recuperaram a função ventricular apresentaram menores tamanhos de infarto, mas maiores valores da fração de ejeção e tempo de desaceleração da onda E que pacientes sem recuperação. Na análise multivariada, observa-se que o tamanho de infarto foi o único fator preditor independente de recuperação funcional após 6 meses de infarto, quando ajustado pela idade, sexo, fração de ejeção e tempo de desaceleração da onda E. Conclusão: Apesar do tratamento agressivo, a disfunção ventricular sistólica continua a ser um evento frequente após o infarto de parede anterior. Adicionalmente, 25% dos pacientes apresentam recuperação funcional. Finalmente, o tamanho do infarto foi o único fator preditor de recuperação funcional após seis meses do infarto agudo do miocárdio.
Arquivos Brasileiros de Cardiologia, 2005
The animals were randomly distributed into the following 2 groups: 1) smokers (S), comprising 10 ... more The animals were randomly distributed into the following 2 groups: 1) smokers (S), comprising 10 animals exposed to cigarette smoke at a rate of 40 cigarettes/day; and 2) control (C), comprising 10 animals not exposed to cigarette smoke. After 4 months, the animals underwent morphological and functional study with echocardiography. The variables studied were analyzed by use of the t test or the Mann-Whitney test.
Nutrition, 2013
Objective: The impact of obesity on ventricular remodeling after myocardial infarction (MI) is st... more Objective: The impact of obesity on ventricular remodeling after myocardial infarction (MI) is still poorly understood. Therefore, the aim of this study was to evaluate the role of waist circumference (WC) and body mass index as predictors of cardiac remodeling in patients after an anterior MI. Methods: Eighty-three consecutive patients with anterior MI were prospectively evaluated. Clinical characteristics and echocardiographic data were analyzed at admission and at a 6-mo follow-up. Ventricular remodeling was defined as a 10% increase in left ventricular end-systolic or enddiastolic diameter at the 6-mo follow-up. Results: In our study, 83 consecutive patients were evaluated (72% men). Ventricular remodeling was present in 31% of the patients (77% men). Patients with remodeling had higher creatine phosphokinase and creatine phosphokinase-MB peak values, a higher resting heart rate, a larger left atrial diameter, and a larger interventricular septum diastolic thickness. In addition, patients with remodeling had lower peak velocity of early ventricular filling deceleration time and ejection fraction. Patients with remodeling presented higher WC values (with remodeling, 99.2 AE 10.4 cm; without remodeling, 93.9 AE 10.8 cm, P ¼ 0.04), but there were no differences in the body mass index values. In the logistic regression analysis, WC, adjusted by age, gender, ejection fraction, and creatine phosphokinase levels, was an independent predictor of left ventricular remodeling (odds ratio 1.067, 95% confidence interval 1.001-1.129, P ¼ 0.02). Conclusion: Waist circumference, but not body mass index, is a predictor of ventricular remodeling after an anterior MI. Therefore, the WC of these patients should be measured in clinical practice.
Nutrition, 2011
Objective: The role of retinoic acid in promoting postnatal heart alterations is still unclear. T... more Objective: The role of retinoic acid in promoting postnatal heart alterations is still unclear. The aim of this study was to evaluate whether the cardiac alterations caused by all-trans-retinoic acid (ATRA) in normal adult rat hearts are physiologic or pathologic and if these alterations are dosedependent. Methods: Rats were allocated into a control group that received a diet without ATRA (n ¼ 16), a group that received 0.3 mg of ATRA/kg of diet (n ¼ 17), a group that received a diet containing 10 mg of ATRA/kg (n ¼ 18), or a group that received 50 mg of ATRA/kg in the diet (n ¼ 18). After 4 wk, the animals were evaluated echocardiographically, morphologically, and biochemically. Results: The 50-mg ATRA group presented cardiac hypertrophy with maintenance of cardiac geometry and increased systolic function, whereas diastolic function was similar to that of the control group. In addition, progressive increases in the ATRA dose resulted in gradual augmentations of left atrial diameter, left ventricular diastolic and systolic diameters, left ventricular mass index, cardiac output, cardiac index, and aortic velocity. The ATRA did not produce alterations in interferon-g and tumor necrosis factor-a cardiac levels, interstitial collagen volume fraction, or the intensity and localization of connexin-43. In addition, no alteration was observed in b-hydroxyacyl coenzyme A dehydrogenase, lactate dehydrogenase, or citrate synthase, suggesting that cardiac energetic metabolism was preserved with ATRA. Conclusion: These results suggest that ATRA produced dose-dependent effects and cardiac remodeling that is more compatible with a physiologic response.
Nutrition, 2006
We studied the effects of -carotene (BC) on ventricular remodeling after myocardial infarction. ... more We studied the effects of -carotene (BC) on ventricular remodeling after myocardial infarction. Methods: Myocardial infarction was induced in Wistar rats that were then treated with a BC diet (500 mg/kg of diet per day; MI-BC; n ϭ 27) or a regular diet (MI; n ϭ 27). Hearts were analyzed in vivo and in vitro after 6 mo. Results: BC caused decreased left ventricular wall thickness (MI ϭ 1.49 Ϯ 0.3 mm, MI-BC ϭ 1.23 Ϯ 0.2 mm, P ϭ 0.027) and increased diastolic (MI ϭ 0.83 Ϯ 0.15 cm 2 , MI-BC ϭ 0.98 Ϯ 0.14 cm 2 , P ϭ 0.020) and systolic (MI ϭ 0.56 Ϯ 0.12 cm 2 , MI-BC ϭ 0.75 Ϯ 0.13 cm 2 , P ϭ 0.002) left ventricular chamber areas. With respect to systolic function, the BC group presented less change in fractional area than did controls (MI ϭ 32.35 Ϯ 6.67, MI-BC ϭ 23.77 Ϯ 6.06, P ϭ 0.004). There was no difference in transmitral diastolic flow velocities between groups. In vitro results showed decreased maximal isovolumetric systolic pressure (MI ϭ 125.5 Ϯ 24.1 mmHg, MI-BC ϭ 95.2 Ϯ 28.4 mmHg, P ϭ 0.019) and increased interstitial myocardial collagen concentration (MI ϭ 3.3 Ϯ 1.2%, MI-BC ϭ 5.8 Ϯ 1.7%, P ϭ 0.004) in BC-treated animals. Infarct sizes were similar between groups (MI ϭ 45.0 Ϯ 6.6%, MI-BC ϭ 48.0 Ϯ 5.8%, P ϭ 0.246). Conclusion: Taken together, these data suggest that BC has adverse effects on ventricular remodeling after myocardial infarction.
Medical Science Monitor, 2012
Background: The consequences of aggressive therapy following a myocardial infarction (MI) on vent... more Background: The consequences of aggressive therapy following a myocardial infarction (MI) on ventricular remodeling are not well established. Thus, the objective of this study was to analyze the prevalence, clinical characteristics, and predictors of left ventricular remodeling in the era of modern medical therapy. Material/Methods: Clinical characteristics and echocardiographic data were analyzed in 66 consecutive patients with anterior infarction at admission and at 6-month follow-up. Ventricular remodeling was defined as an increase of 10% in ventricular end-systolic or end-diastolic diameter.
International Journal of Cardiology, 2012
Background: The AIN-93 diet was proposed by the American Institute of Nutrition with the objectiv... more Background: The AIN-93 diet was proposed by the American Institute of Nutrition with the objective of standardising studies in experimental nutrition. Our objective was to analyze the effects of AIN-93 diet after myocardial infarction in rats. Methods: Post weaning, the animals were divided into two groups: control (C, n = 62), fed the standard diet of our laboratory (Labina); AIN-93 Group (n = 70), fed the AIN-93 diet. Achieving 250 g, the animals were subjected to myocardial infarction. Results: Early mortality was increased in AIN-93 animals, associated with lower serum levels of calcium, magnesium, potassium, sodium, and phosphorus. On the other hand, after 90 days, AIN-93 showed smaller normalized left ventricular dimensions. The caloric and carbohydrate intake was smaller, but the fat intake was higher in AIN-93 rats. AIN-93 group also showed increased levels of β-hydroxyacylcoenzyme A dehydrogenase and citrate synthase. In addition, serum levels of insulin and cardiac levels of malondialdehyde, metalloproteinases-2 and-9, and TNF-α and IFN-γ were decreased in the AIN-93 group. Conclusion: AIN-93 diet increased early mortality, while attenuated the chronic remodeling process after experimental coronary occlusion. Therefore, this diet has biological effects and should be use with attention in this model.
International Journal of Cardiology, 2011
International Journal of Cardiology, 2013
Background: Currently, 13-cis-retinoic acid (13-cis-RA) is the most effective therapy for acne. I... more Background: Currently, 13-cis-retinoic acid (13-cis-RA) is the most effective therapy for acne. Isotretinoin, a first-generation synthetic 13-cis-RA compound, is associated with numerous adverse effects. To investigate the cardiac effects of 13-cis-RA, acne patients receiving 13-cis-RA were studied. Methods: Twenty male patients with acne were enrolled in the study. Patients were treated with a dose of 0.5 mg/kg/d of isotretinoin. All participants were assessed prior to treatment and after 10 weeks of therapy with Doppler-echocardiogram. Results: Patients showed reductions in right atrium vertical diameter, left atrium longitudinal diameter, left atrium volume and left ventricular diastolic diameter over the course of treatment. Significant increases in interventricular septum diastolic thickness, posterior wall diastolic thickness, relative wall relative thickness and left ventricle (LV) mass were observed. The LV mass index showed an increase in ventricular mass and a decrease in the cavity size. Examining LV systolic function, a decrease was observed for the cardiac index. Conclusion: In this study, 10 weeks of 13-cis-RA therapy at a dose of 0.5 mg/kg/d was found to promote concentric-type heart remodeling due to the occurrence of two associated events: heart hypertrophy and hypovolemia.
European Journal of Heart Failure, 2007
Aim: To investigate the role of MMP-2 and MMP-9 in cardiac remodelling induced by tobacco smoke e... more Aim: To investigate the role of MMP-2 and MMP-9 in cardiac remodelling induced by tobacco smoke exposure in rats. Methods: Rats were allocated into two groups: C (n = 9): control animals; ETS (n = 9): exposed to tobacco smoke. After 4months, the animals underwent echocardiography, morphometric study and determination of MMP-2 and MMP-9 activity. Results: ETS rats had larger diastolic (C = 15.6 ± 1.2 mm/kg, ETS = 18.0 ± 0.9 mm/kg; p b 0.001) and systolic (C = 7.3 ± 1.2 mm/kg, ETS = 9.2 ± 0.9 mm/kg; p = 0.001) ventricular diameters adjusted for body weight. Fractional shortening (C = 53 ± 4.8%, ETS = 48 ± 3.3%; p = 0.031) and ejection fraction (C = 0.89 ± 0.03, ETS = 0.86 ± 0.02; p = 0.030) were smaller in the ETS group. Myocyte cross-sectional area (C = 245 ± 8 μm 2 , ETS = 253 ± 8 μm 2 ; p = 0.028) was higher in ETS rats. There were no differences in MMP-2 (C = 50 ± 14%; ETS = 43 ± 11%, p =0.228) or MMP-9 (C = 0.36 ± 0.3%; ETS = 0.62 ± 0.3%, p = 0.630) activity between the groups. Conclusion: MMP-2 and MMP-9 did not participate in the remodelling process induced by tobacco smoke exposure.
Cellular Physiology and Biochemistry, 2010
Background/Aims: The role of tissue vitamin-A insufficiency on post-infarction ventricular remode... more Background/Aims: The role of tissue vitamin-A insufficiency on post-infarction ventricular remodeling is unknown. We tested the hypothesis that cardiac vitamin A insufficiency on post-infarction is associated with adverse myocardial remodeling. Methods: After infarction, rats were allocated into two groups: C (controls, n=25); VA (dietary vitamin A restriction, n= 26). After 3 months, the animals were submitted to echocardiogram, morphometric and biochemical analysis. Results: Rats fed the vitamin-A-deficient diet had lower heart and liver retinol concentration and normal plasma retinol. There were no differences in infarct size between the groups. VA showed higher diastolic left ventricular area normalised by body weight (C= 1.81 ± 0.4 cm2/kg, VA= 2.15 ± 0.3 cm2/ kg; p=0.03), left ventricular diameter (C= 9.4 ± 1.4 mm, VA= 10.5 ± 1.2 mm; p=0.04), but similar systolic ventricular fractional area change (C= 33.0 ± 10.0 %, VA= 32.1 ± 8.7 %; p=0.82). VA showed decreased isovolumetric relaxation time normalised by heart rate (C= 68.8 ± 11.4 ms, VA= 56.3 ± 16.8 ms; p=0.04). VA showed higher interstitial collagen fraction (C= 2.8 ± 0.9 %, VA= 3.7 ± 1.1 %; p=0.05). There were no differences in myosin heavy chain expression, metalloproteinase 2 and 9 activation, or IFN-γ and TNF-α cardiac levels. Conclusion: Local tissue vitamin A insufficiency intensified ventricular remodeling after MI, worsening diastolic dysfunction.
Cellular Physiology and Biochemistry, 2010
Background/Aims: Experimental studies suggest that vitamin A plays a role in regulating cardiac s... more Background/Aims: Experimental studies suggest that vitamin A plays a role in regulating cardiac structure and function. We tested the hypothesis that cardiac vitamin A deficiency is associated with adverse myocardial remodeling in young adult rats. Methods: Two groups of young female rats, control (C-n = 29) and tissue vitamin A deficient (RVA-n = 31), were subjected to transthoracic echocardiography exam, isolated rat heart study and biochemical study. Results: The RVA rats showed a reduced total vitamin A concentration in both the liver and heart [vitamin A in heart, µmol/kg (C = 0.95 ± 0.44 and RVA = 0.24 ± 0.16, p = 0.01)] with the same serum retinol levels (C = 0.73 ± 0.29 µmol/L e RVA = 0.62 ± 0.17 µmol/L, p = 0.34). The RVA rats showed higher left ventricular diameters and reduced systolic function. The RVA rats also demonstrated increased lipid hydroperoxide/total antioxidant capacity ratio and cardiac levels of IFN-γ and TNF-α but not of metalloproteinase (MMP)-2 and-9 activity. On the other hand, the RVA rats had decreased levels of β-hydroxyacylcoenzyme A dehydrogenase and lactate dehydrogenase. Conclusions: Tissue vitamin A deficiency stimulated cardiac remodeling and ventricular dysfunction. Additionally, the data support the involvement of oxidative stress, energy metabolism, and cytokine production in this remodeling process.
Cellular Physiology and Biochemistry, 2011
Background/Aims: To investigate the effect of taurine on cardiac remodeling induced by smoking. M... more Background/Aims: To investigate the effect of taurine on cardiac remodeling induced by smoking. Methods: In the first step, rats were allocated into two groups: Group C (n=14): control; Group T (n=14): treated with taurine (3% in drinking water), for three months. In the second step, rats were allocated into two groups: Group ETS (n=9): rats exposed to tobacco smoke; Group ETS-T (n=9): rats exposed to tobacco smoke and treated with taurine for two months. Results: After three months, taurine presented no effects on morphological or functional variables of normal rats assessed by echocardiogram. On the other hand, after two months, ETS-T group presented higher LV wall thickness (ETS=1.30 (1.20-1.42); ETS-T=1.50 (1.40-1.50); p=0.029), E/A ratio (ETS=1.13±0.13; ETS-T=1.37±0.26; p=0.028), and isovolumetric relaxation time normalized for heart rate (ETS=53.9±4.33; ETS-T=72.5±12.0; p<0.001). The cardiac activity of the lactate dehydrogenase was higher in the ETS-T group (ETS=204±14 nmol/mg protein; ETS-T=232±12 nmol/mg protein; p<0.001). ETS-T group presented lower levels of phospholamban (ETS=1.00±0.13; ETS-T=0.82±0.06; p=0.026), phosphorylated phospholamban at Ser16 (ETS=1.00±0.14;ETS-T=0.63±0.10;p=0.003), and phosphorylated phosfolamban/phospholamban ratio (ETS=1.01±0.17; ETS-T=0.77±0.11; p=0.050). Conclusion: In normal rats, taurine produces no effects on cardiac morphological or functional variables. On the other hand, in rats exposed to cigarette smoke, taurine supplementation increases wall thickness and worsens diastolic function, associated with alterations in calcium handling protein and cardiac energy metabolism.
Cellular Physiology and Biochemistry, 2011
Background: Recent studies have assessed the direct effects of smoking on cardiac remodeling and ... more Background: Recent studies have assessed the direct effects of smoking on cardiac remodeling and function. However, the mechanisms of these alterations remain unknown. The aim of this study was to investigate de role of cardiac NADPH oxidase and antioxidant enzyme system on ventricular remodeling induced by tobacco smoke. Methods: Male Wistar rats that weighed 200-230 g were divided into a control group (C) and an experimental group that was exposed to tobacco smoke for a period of two months (ETS). After the two-month exposure period, morphological, biochemical and functional analyses were performed. Results: The myocyte crosssectional area and left ventricle end-diastolic dimension was increased 16.2% and 33.7%, respectively, in the ETS group. The interstitial collagen volume fraction was also higher in ETS group compared to the controls. In addition to these morphological changes, the ejection fraction and fractional shortening were decreased in the ETS group. Importantly, these alterations were related to augmented heart oxidative stress, which was characterized by an increase in NADPH oxidase activity, increased levels of lipid hydroperoxide and depletion of antioxidant enzymes (e.g., catalase, superoxide dismutase and glutathione peroxidase). In addition, cardiac levels of IFN-γ, TNF-α and IL-10 were not different between the groups. Conclusion: Cardiac alterations that are induced by smoking are associated with increased NADPH oxidase activity, suggesting that this pathway plays a role in the ventricular remodeling induced by exposure to tobacco smoke.
Arquivos Brasileiros De Cardiologia, Jun 1, 2009
Arquivos Brasileiros de Cardiologia
To evaluate the role of cigarette smoke exposure (CSE) on ventricular remodeling following acute ... more To evaluate the role of cigarette smoke exposure (CSE) on ventricular remodeling following acute myocardial infarction (AMI). METHODS Rats were submitted to myocardial infarction and divided into two groups: C (control, n = 31) and F (CSE: 40 cigarettes/day, n = 22). After 6 months, the survivors were submitted to echocardiogram, functional study with isolated heart, and morphometric analysis. For comparison purposes, we used the t test (mean ± standard deviation) or the Mann-Whitney test (with median and 25 th and 75 th percentiles). RESULTS The CSE animals tended to have larger diastolic (C = 1.5 ± 0.4 mm 2 , F = 1.9 ± 0.4 mm 2 ; p = 0.08) and systolic (C = 1.05 ± 0.3 mm 2 , F = 1.32 ± 0.4 mm 2 ; p = 0.08) left ventricular(LV) areas. The systolic function of the LV, assessed according to the fractional area change, tended to be impaired in CSE animals (C = 31.9 ± 9.3%, F = 25.5 ± 7.6%; p = 0.08). The-dp/dt values for CSE animals were statistically lower (C = 1474 ± 397 mmHg, F = 916 ± 261 mmHg; p = 0.02) than for control animals. The CSE animals presented higher right ventricle (RV) weight adjusted for body weight (C = 0.8 ± 0.3 mg/g, F = 1.3 ± 0.4 mg/g; p = 0.01), higher content of water in lungs (C = 4.8 (4.3-4.8)%, F = 5.4 (5.1-5.5); p = 0.03), and larger LV myocyte cross-sectional areas (C = 239.8 ± 5.8 µm 2 , F = 253.9 ± 7.9 µm 2 ; p = 0.01). CONCLUSION Cigarette smoke exposure intensifies ventricular remodeling following acute myocardial infarction.
Medical science monitor : international medical journal of experimental and clinical research, 2010
To investigate the effect of lisinopril on cardiac remodeling induced by smoking. Rats were alloc... more To investigate the effect of lisinopril on cardiac remodeling induced by smoking. Rats were allocated into 3 groups: group CON (n=8): control; group CSE (n=8): cigarette smoke exposure; group CSE-LIS (n=8): exposed to tobacco smoke and treated with lisinopril. After 2 months, the tail systolic pressure was lower in CSE-LIS (CON=116 +/-27 mm Hg, CSE=126+/-16, CSE-LIS=89+/-12; P<.001). CSE animals showed higher left ventricular systolic diameter (CON=8.25+/-2.16 mm/kg, CSE=11.5+/-1.3, CSE-LIS=9.27+/-2.00; P=.009) and myocyte cross-sectional area (CON=245+/-8 microm2, CSE=260+/-17, CSE-LIS=238+/-12; P=.01) than CON and CSE-LIS. The ejection fraction (CON =0.91+/-0.02, CSE=0.86+/-0.02, CSE-LIS=0.92+/-0.03; P=.002) and fractional shortening (CON=55.7+/-4.41%, CSE=48.7+/-3.43, CSE-LI=58.2+/-7.63; P=.006) were lower in CSE group than CON and CSE-LIS. CSE and CSE-LIS animals showed higher collagen amounts (CON=3.49+/-0.95%, CSE= 5.01+/-1.58, CSE-LIS=5.27+/-0.62; P=.009) than CON. CON gro...
Acta cardiologica, 2011
Our objective was to test the hypothesis that retinoic acid supplementation could attenuate ventr... more Our objective was to test the hypothesis that retinoic acid supplementation could attenuate ventricular remodelling induced by tobacco smoke exposure in rats. Wistar rats were allocated into three groups: control (C, n = 8); exposed to tobacco smoke (ETS, n = 9); exposed to tobacco smoke and all-trans-retinoic acid (ETS-RA, n = 9). After two months, cardiac function and geometry were assessed by echocardiography, and geometry changes were confirmed by morphometric analysis. Data are expressed as mean +/- SD or medians (including the lower quartile and upper quartile). ETS showed higher normalized left ventricular diastolic diameters than groups C and ETS-RA (C = 18.4 +/- 3.57 mm/kg, ETS = 23.0 +/- 1.8, ETS-RA = 19.5 +/- 0.99; P <0.05) and systolic diameters (C = 8.25 +/- 2.16 mm/kg, ETS = 11.5 +/- 1.31, ETS-RA = 8.25 +/- 0.71 mm/kg; P < 0.05). ETS showed reduced ejection fraction (C= 91 +/- 2.0, ETS = 87 +/- 3.0, ETS-RA = 92 +/- 3.0; P < 0.05) and fractional shortening (C =...
The Journal of nutrition, 2005
The objective of this study was to evaluate the role of retinoic acid in experimental postinfarct... more The objective of this study was to evaluate the role of retinoic acid in experimental postinfarction myocardial remodeling. Wistar rats were subjected to myocardial infarction (MI) and treated with retinoic acid (RA), 0.3 mg/(kg x d) (MI-RA, n = 29), or fed a control diet (MI, n = 34). After 6 mo, the surviving rats (MI-RA = 18 and MI = 22) underwent echocardiograms, and isolated hearts were tested for function in vitro. The cross-sectional area of the myocyte (CSA) and interstitial collagen fraction (IC) were measured in a cross section of the heart stained by hematoxylin-eosin and picrosirius red, respectively. The CSA was smaller in the MI-RA group [229 (220,234) microm2] [medians (lower quartile, upper quartile)] than in the MI group [238 (232,241) microm2] (P = 0.01) and IC was smaller in the MI-RA group [2.4 (1.7, 3.1)%] than in the MI group [3.5 (2.6, 3.9)%] (P = 0.05). The infarct size did not differ between the groups [MI = 44.6 (40.8, 48.4)%, MI-RA = 45 (38.6, 47.2)%]. Max...
The Journal of nutrition, 2005
The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in ... more The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in rats that were or were not supplemented with dietary beta-carotene (BC), on ventricular remodeling and survival after myocardial infarction (MI). Rats (n = 189) were allocated to 4 groups: the control group, n = 45; group BC administered 500 mg/kg diet, n = 49, BC supplemented rats; group ETS, n = 55, rats exposed to tobacco smoke; and group BC+ETS, n = 40. Wistar rats weighing 100 g were administered one of the treatments until they weighed 200 to 250 g (approximately 5 wk). The ETS rats were exposed to cigarette smoke for 30 min 4 times/d, in a chamber connected to a smoking device. After reaching a weight of 200-250 g, rats were subjected to experimental MI (coronary artery occlusion) and mortality rates were determined over the next 105 d. In addition, echocardiographic, isolated heart, morphometrical, and biochemical studies were performed. Mortality data were tested using Kaplan-Me...
Arquivos Brasileiros de Cardiologia, 2014
Fundamento: Os efeitos da terapêutica moderna na recuperação funcional após o infarto agudo do mi... more Fundamento: Os efeitos da terapêutica moderna na recuperação funcional após o infarto agudo do miocárdio não são conhecidos. Objetivos: Avaliar os fatores preditores da recuperação funcional sistólica após infarto agudo do miocárdio de parede anterior em pacientes submetidos à terapia moderna (reperfusão, antiagregação plaquetária agressiva, inibidores da enzima conversora da angiotensina e betabloqueadores). Métodos: Foram incluídos 94 pacientes consecutivos com infarto agudo do miocárdio com supradesnivelamento do segmento ST. Ecocardiogramas foram realizados na fase intra-hospitalar e após 6 meses. Disfunção sistólica foi definida pela presença de fração de ejeção de valor < 50%. Resultados: No ecocardiograma inicial, 64% dos pacientes apresentaram disfunção sistólica. Os pacientes com disfunção ventricular apresentaram tamanhos maiores de infarto, avaliados pelas enzimas creatinofosfoquinase total e isoenzima MB, que os pacientes sem disfunção. Adicionalmente, 24,5% dos pacientes inicialmente com disfunção sistólica apresentaram recuperação no período de 6 meses após o infarto agudo do miocárdio. Os pacientes que recuperaram a função ventricular apresentaram menores tamanhos de infarto, mas maiores valores da fração de ejeção e tempo de desaceleração da onda E que pacientes sem recuperação. Na análise multivariada, observa-se que o tamanho de infarto foi o único fator preditor independente de recuperação funcional após 6 meses de infarto, quando ajustado pela idade, sexo, fração de ejeção e tempo de desaceleração da onda E. Conclusão: Apesar do tratamento agressivo, a disfunção ventricular sistólica continua a ser um evento frequente após o infarto de parede anterior. Adicionalmente, 25% dos pacientes apresentam recuperação funcional. Finalmente, o tamanho do infarto foi o único fator preditor de recuperação funcional após seis meses do infarto agudo do miocárdio.
Arquivos Brasileiros de Cardiologia, 2005
The animals were randomly distributed into the following 2 groups: 1) smokers (S), comprising 10 ... more The animals were randomly distributed into the following 2 groups: 1) smokers (S), comprising 10 animals exposed to cigarette smoke at a rate of 40 cigarettes/day; and 2) control (C), comprising 10 animals not exposed to cigarette smoke. After 4 months, the animals underwent morphological and functional study with echocardiography. The variables studied were analyzed by use of the t test or the Mann-Whitney test.
Nutrition, 2013
Objective: The impact of obesity on ventricular remodeling after myocardial infarction (MI) is st... more Objective: The impact of obesity on ventricular remodeling after myocardial infarction (MI) is still poorly understood. Therefore, the aim of this study was to evaluate the role of waist circumference (WC) and body mass index as predictors of cardiac remodeling in patients after an anterior MI. Methods: Eighty-three consecutive patients with anterior MI were prospectively evaluated. Clinical characteristics and echocardiographic data were analyzed at admission and at a 6-mo follow-up. Ventricular remodeling was defined as a 10% increase in left ventricular end-systolic or enddiastolic diameter at the 6-mo follow-up. Results: In our study, 83 consecutive patients were evaluated (72% men). Ventricular remodeling was present in 31% of the patients (77% men). Patients with remodeling had higher creatine phosphokinase and creatine phosphokinase-MB peak values, a higher resting heart rate, a larger left atrial diameter, and a larger interventricular septum diastolic thickness. In addition, patients with remodeling had lower peak velocity of early ventricular filling deceleration time and ejection fraction. Patients with remodeling presented higher WC values (with remodeling, 99.2 AE 10.4 cm; without remodeling, 93.9 AE 10.8 cm, P ¼ 0.04), but there were no differences in the body mass index values. In the logistic regression analysis, WC, adjusted by age, gender, ejection fraction, and creatine phosphokinase levels, was an independent predictor of left ventricular remodeling (odds ratio 1.067, 95% confidence interval 1.001-1.129, P ¼ 0.02). Conclusion: Waist circumference, but not body mass index, is a predictor of ventricular remodeling after an anterior MI. Therefore, the WC of these patients should be measured in clinical practice.
Nutrition, 2011
Objective: The role of retinoic acid in promoting postnatal heart alterations is still unclear. T... more Objective: The role of retinoic acid in promoting postnatal heart alterations is still unclear. The aim of this study was to evaluate whether the cardiac alterations caused by all-trans-retinoic acid (ATRA) in normal adult rat hearts are physiologic or pathologic and if these alterations are dosedependent. Methods: Rats were allocated into a control group that received a diet without ATRA (n ¼ 16), a group that received 0.3 mg of ATRA/kg of diet (n ¼ 17), a group that received a diet containing 10 mg of ATRA/kg (n ¼ 18), or a group that received 50 mg of ATRA/kg in the diet (n ¼ 18). After 4 wk, the animals were evaluated echocardiographically, morphologically, and biochemically. Results: The 50-mg ATRA group presented cardiac hypertrophy with maintenance of cardiac geometry and increased systolic function, whereas diastolic function was similar to that of the control group. In addition, progressive increases in the ATRA dose resulted in gradual augmentations of left atrial diameter, left ventricular diastolic and systolic diameters, left ventricular mass index, cardiac output, cardiac index, and aortic velocity. The ATRA did not produce alterations in interferon-g and tumor necrosis factor-a cardiac levels, interstitial collagen volume fraction, or the intensity and localization of connexin-43. In addition, no alteration was observed in b-hydroxyacyl coenzyme A dehydrogenase, lactate dehydrogenase, or citrate synthase, suggesting that cardiac energetic metabolism was preserved with ATRA. Conclusion: These results suggest that ATRA produced dose-dependent effects and cardiac remodeling that is more compatible with a physiologic response.
Nutrition, 2006
We studied the effects of -carotene (BC) on ventricular remodeling after myocardial infarction. ... more We studied the effects of -carotene (BC) on ventricular remodeling after myocardial infarction. Methods: Myocardial infarction was induced in Wistar rats that were then treated with a BC diet (500 mg/kg of diet per day; MI-BC; n ϭ 27) or a regular diet (MI; n ϭ 27). Hearts were analyzed in vivo and in vitro after 6 mo. Results: BC caused decreased left ventricular wall thickness (MI ϭ 1.49 Ϯ 0.3 mm, MI-BC ϭ 1.23 Ϯ 0.2 mm, P ϭ 0.027) and increased diastolic (MI ϭ 0.83 Ϯ 0.15 cm 2 , MI-BC ϭ 0.98 Ϯ 0.14 cm 2 , P ϭ 0.020) and systolic (MI ϭ 0.56 Ϯ 0.12 cm 2 , MI-BC ϭ 0.75 Ϯ 0.13 cm 2 , P ϭ 0.002) left ventricular chamber areas. With respect to systolic function, the BC group presented less change in fractional area than did controls (MI ϭ 32.35 Ϯ 6.67, MI-BC ϭ 23.77 Ϯ 6.06, P ϭ 0.004). There was no difference in transmitral diastolic flow velocities between groups. In vitro results showed decreased maximal isovolumetric systolic pressure (MI ϭ 125.5 Ϯ 24.1 mmHg, MI-BC ϭ 95.2 Ϯ 28.4 mmHg, P ϭ 0.019) and increased interstitial myocardial collagen concentration (MI ϭ 3.3 Ϯ 1.2%, MI-BC ϭ 5.8 Ϯ 1.7%, P ϭ 0.004) in BC-treated animals. Infarct sizes were similar between groups (MI ϭ 45.0 Ϯ 6.6%, MI-BC ϭ 48.0 Ϯ 5.8%, P ϭ 0.246). Conclusion: Taken together, these data suggest that BC has adverse effects on ventricular remodeling after myocardial infarction.
Medical Science Monitor, 2012
Background: The consequences of aggressive therapy following a myocardial infarction (MI) on vent... more Background: The consequences of aggressive therapy following a myocardial infarction (MI) on ventricular remodeling are not well established. Thus, the objective of this study was to analyze the prevalence, clinical characteristics, and predictors of left ventricular remodeling in the era of modern medical therapy. Material/Methods: Clinical characteristics and echocardiographic data were analyzed in 66 consecutive patients with anterior infarction at admission and at 6-month follow-up. Ventricular remodeling was defined as an increase of 10% in ventricular end-systolic or end-diastolic diameter.
International Journal of Cardiology, 2012
Background: The AIN-93 diet was proposed by the American Institute of Nutrition with the objectiv... more Background: The AIN-93 diet was proposed by the American Institute of Nutrition with the objective of standardising studies in experimental nutrition. Our objective was to analyze the effects of AIN-93 diet after myocardial infarction in rats. Methods: Post weaning, the animals were divided into two groups: control (C, n = 62), fed the standard diet of our laboratory (Labina); AIN-93 Group (n = 70), fed the AIN-93 diet. Achieving 250 g, the animals were subjected to myocardial infarction. Results: Early mortality was increased in AIN-93 animals, associated with lower serum levels of calcium, magnesium, potassium, sodium, and phosphorus. On the other hand, after 90 days, AIN-93 showed smaller normalized left ventricular dimensions. The caloric and carbohydrate intake was smaller, but the fat intake was higher in AIN-93 rats. AIN-93 group also showed increased levels of β-hydroxyacylcoenzyme A dehydrogenase and citrate synthase. In addition, serum levels of insulin and cardiac levels of malondialdehyde, metalloproteinases-2 and-9, and TNF-α and IFN-γ were decreased in the AIN-93 group. Conclusion: AIN-93 diet increased early mortality, while attenuated the chronic remodeling process after experimental coronary occlusion. Therefore, this diet has biological effects and should be use with attention in this model.
International Journal of Cardiology, 2011
International Journal of Cardiology, 2013
Background: Currently, 13-cis-retinoic acid (13-cis-RA) is the most effective therapy for acne. I... more Background: Currently, 13-cis-retinoic acid (13-cis-RA) is the most effective therapy for acne. Isotretinoin, a first-generation synthetic 13-cis-RA compound, is associated with numerous adverse effects. To investigate the cardiac effects of 13-cis-RA, acne patients receiving 13-cis-RA were studied. Methods: Twenty male patients with acne were enrolled in the study. Patients were treated with a dose of 0.5 mg/kg/d of isotretinoin. All participants were assessed prior to treatment and after 10 weeks of therapy with Doppler-echocardiogram. Results: Patients showed reductions in right atrium vertical diameter, left atrium longitudinal diameter, left atrium volume and left ventricular diastolic diameter over the course of treatment. Significant increases in interventricular septum diastolic thickness, posterior wall diastolic thickness, relative wall relative thickness and left ventricle (LV) mass were observed. The LV mass index showed an increase in ventricular mass and a decrease in the cavity size. Examining LV systolic function, a decrease was observed for the cardiac index. Conclusion: In this study, 10 weeks of 13-cis-RA therapy at a dose of 0.5 mg/kg/d was found to promote concentric-type heart remodeling due to the occurrence of two associated events: heart hypertrophy and hypovolemia.
European Journal of Heart Failure, 2007
Aim: To investigate the role of MMP-2 and MMP-9 in cardiac remodelling induced by tobacco smoke e... more Aim: To investigate the role of MMP-2 and MMP-9 in cardiac remodelling induced by tobacco smoke exposure in rats. Methods: Rats were allocated into two groups: C (n = 9): control animals; ETS (n = 9): exposed to tobacco smoke. After 4months, the animals underwent echocardiography, morphometric study and determination of MMP-2 and MMP-9 activity. Results: ETS rats had larger diastolic (C = 15.6 ± 1.2 mm/kg, ETS = 18.0 ± 0.9 mm/kg; p b 0.001) and systolic (C = 7.3 ± 1.2 mm/kg, ETS = 9.2 ± 0.9 mm/kg; p = 0.001) ventricular diameters adjusted for body weight. Fractional shortening (C = 53 ± 4.8%, ETS = 48 ± 3.3%; p = 0.031) and ejection fraction (C = 0.89 ± 0.03, ETS = 0.86 ± 0.02; p = 0.030) were smaller in the ETS group. Myocyte cross-sectional area (C = 245 ± 8 μm 2 , ETS = 253 ± 8 μm 2 ; p = 0.028) was higher in ETS rats. There were no differences in MMP-2 (C = 50 ± 14%; ETS = 43 ± 11%, p =0.228) or MMP-9 (C = 0.36 ± 0.3%; ETS = 0.62 ± 0.3%, p = 0.630) activity between the groups. Conclusion: MMP-2 and MMP-9 did not participate in the remodelling process induced by tobacco smoke exposure.
Cellular Physiology and Biochemistry, 2010
Background/Aims: The role of tissue vitamin-A insufficiency on post-infarction ventricular remode... more Background/Aims: The role of tissue vitamin-A insufficiency on post-infarction ventricular remodeling is unknown. We tested the hypothesis that cardiac vitamin A insufficiency on post-infarction is associated with adverse myocardial remodeling. Methods: After infarction, rats were allocated into two groups: C (controls, n=25); VA (dietary vitamin A restriction, n= 26). After 3 months, the animals were submitted to echocardiogram, morphometric and biochemical analysis. Results: Rats fed the vitamin-A-deficient diet had lower heart and liver retinol concentration and normal plasma retinol. There were no differences in infarct size between the groups. VA showed higher diastolic left ventricular area normalised by body weight (C= 1.81 ± 0.4 cm2/kg, VA= 2.15 ± 0.3 cm2/ kg; p=0.03), left ventricular diameter (C= 9.4 ± 1.4 mm, VA= 10.5 ± 1.2 mm; p=0.04), but similar systolic ventricular fractional area change (C= 33.0 ± 10.0 %, VA= 32.1 ± 8.7 %; p=0.82). VA showed decreased isovolumetric relaxation time normalised by heart rate (C= 68.8 ± 11.4 ms, VA= 56.3 ± 16.8 ms; p=0.04). VA showed higher interstitial collagen fraction (C= 2.8 ± 0.9 %, VA= 3.7 ± 1.1 %; p=0.05). There were no differences in myosin heavy chain expression, metalloproteinase 2 and 9 activation, or IFN-γ and TNF-α cardiac levels. Conclusion: Local tissue vitamin A insufficiency intensified ventricular remodeling after MI, worsening diastolic dysfunction.
Cellular Physiology and Biochemistry, 2010
Background/Aims: Experimental studies suggest that vitamin A plays a role in regulating cardiac s... more Background/Aims: Experimental studies suggest that vitamin A plays a role in regulating cardiac structure and function. We tested the hypothesis that cardiac vitamin A deficiency is associated with adverse myocardial remodeling in young adult rats. Methods: Two groups of young female rats, control (C-n = 29) and tissue vitamin A deficient (RVA-n = 31), were subjected to transthoracic echocardiography exam, isolated rat heart study and biochemical study. Results: The RVA rats showed a reduced total vitamin A concentration in both the liver and heart [vitamin A in heart, µmol/kg (C = 0.95 ± 0.44 and RVA = 0.24 ± 0.16, p = 0.01)] with the same serum retinol levels (C = 0.73 ± 0.29 µmol/L e RVA = 0.62 ± 0.17 µmol/L, p = 0.34). The RVA rats showed higher left ventricular diameters and reduced systolic function. The RVA rats also demonstrated increased lipid hydroperoxide/total antioxidant capacity ratio and cardiac levels of IFN-γ and TNF-α but not of metalloproteinase (MMP)-2 and-9 activity. On the other hand, the RVA rats had decreased levels of β-hydroxyacylcoenzyme A dehydrogenase and lactate dehydrogenase. Conclusions: Tissue vitamin A deficiency stimulated cardiac remodeling and ventricular dysfunction. Additionally, the data support the involvement of oxidative stress, energy metabolism, and cytokine production in this remodeling process.
Cellular Physiology and Biochemistry, 2011
Background/Aims: To investigate the effect of taurine on cardiac remodeling induced by smoking. M... more Background/Aims: To investigate the effect of taurine on cardiac remodeling induced by smoking. Methods: In the first step, rats were allocated into two groups: Group C (n=14): control; Group T (n=14): treated with taurine (3% in drinking water), for three months. In the second step, rats were allocated into two groups: Group ETS (n=9): rats exposed to tobacco smoke; Group ETS-T (n=9): rats exposed to tobacco smoke and treated with taurine for two months. Results: After three months, taurine presented no effects on morphological or functional variables of normal rats assessed by echocardiogram. On the other hand, after two months, ETS-T group presented higher LV wall thickness (ETS=1.30 (1.20-1.42); ETS-T=1.50 (1.40-1.50); p=0.029), E/A ratio (ETS=1.13±0.13; ETS-T=1.37±0.26; p=0.028), and isovolumetric relaxation time normalized for heart rate (ETS=53.9±4.33; ETS-T=72.5±12.0; p<0.001). The cardiac activity of the lactate dehydrogenase was higher in the ETS-T group (ETS=204±14 nmol/mg protein; ETS-T=232±12 nmol/mg protein; p<0.001). ETS-T group presented lower levels of phospholamban (ETS=1.00±0.13; ETS-T=0.82±0.06; p=0.026), phosphorylated phospholamban at Ser16 (ETS=1.00±0.14;ETS-T=0.63±0.10;p=0.003), and phosphorylated phosfolamban/phospholamban ratio (ETS=1.01±0.17; ETS-T=0.77±0.11; p=0.050). Conclusion: In normal rats, taurine produces no effects on cardiac morphological or functional variables. On the other hand, in rats exposed to cigarette smoke, taurine supplementation increases wall thickness and worsens diastolic function, associated with alterations in calcium handling protein and cardiac energy metabolism.
Cellular Physiology and Biochemistry, 2011
Background: Recent studies have assessed the direct effects of smoking on cardiac remodeling and ... more Background: Recent studies have assessed the direct effects of smoking on cardiac remodeling and function. However, the mechanisms of these alterations remain unknown. The aim of this study was to investigate de role of cardiac NADPH oxidase and antioxidant enzyme system on ventricular remodeling induced by tobacco smoke. Methods: Male Wistar rats that weighed 200-230 g were divided into a control group (C) and an experimental group that was exposed to tobacco smoke for a period of two months (ETS). After the two-month exposure period, morphological, biochemical and functional analyses were performed. Results: The myocyte crosssectional area and left ventricle end-diastolic dimension was increased 16.2% and 33.7%, respectively, in the ETS group. The interstitial collagen volume fraction was also higher in ETS group compared to the controls. In addition to these morphological changes, the ejection fraction and fractional shortening were decreased in the ETS group. Importantly, these alterations were related to augmented heart oxidative stress, which was characterized by an increase in NADPH oxidase activity, increased levels of lipid hydroperoxide and depletion of antioxidant enzymes (e.g., catalase, superoxide dismutase and glutathione peroxidase). In addition, cardiac levels of IFN-γ, TNF-α and IL-10 were not different between the groups. Conclusion: Cardiac alterations that are induced by smoking are associated with increased NADPH oxidase activity, suggesting that this pathway plays a role in the ventricular remodeling induced by exposure to tobacco smoke.