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The aim of this study was to evaluate the impact of ovariectomy on oxidative stress in the right ventricle (RV) of female rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). Rats were divided into 4 groups (n = 6 per group): sham(S), sham + MCT (SM), ovariectomized(O), andovariectomized + MCT(OM). MCT(60mg x [kg.sup.-1] i.p.) was injected 1 week after ovariectomy or sham surgery. Three weeks later, echocardiographic analysis and RV catheterisation were performed. RV morphometric, biochemical, and protein expression analysis through Western blotting were done. MCT promoted a slight increase in pulmonary artery pressure, without differences between the SM and OM groups, but did not induce RV hypertrophy. RV hydrogen peroxide increased in the MCT groups, but SOD, CAT, and GPx activities were also enhanced. Non-classical antioxidant defenses diminished in ovariectomized groups, probably due to a decrease in the nuclear factor Nrf2. Hemoxygenase-1 and thioredoxin-1 protein expression was increased in the OM group compared with SM, being accompanied by an elevation in the estrogen receptor [beta] (ER-[beta]). Hemoxygenase-1 and thioredoxin-1 may be involved in the modulation of oxidative stress in the OM group, and this could be responsible for attenuation of PAH and RV remodeling. Key words: oxidative stress, estrogen, hemoxygenase, thioredoxin, pulmonary hypertension. Cette etude avait pour but d'evaluer l'incidence de l'ovariectomie sur le stress oxydatif dans le ventricule droit (VD) de rates atteintes d'hypertension de l'artere pulmonaire (HAP) provoquee par la monocrotaline (MCT). Les rates etaient reparties dans 4 groupes (n = 6 par groupe) : intervention factice (S pour << sham >>), sham + MCT (SM), ovariectomie (O) et ovariectomie + MCT (OM). Nous avons injecte de la MCT (60 mg x [kg.sup.-1] i.p.) une semaine apres l'ovariectomie ou l'intervention chirurgicale factice. Trois semaines plus tard, nous avons effectue une etude echocardiographique et un catheterisme du VD. Nous avons effectue une analyse morphometrique du VD ainsi que des analyses biochimiques et d'expression par immunobuvardage de western. La MCT favorisait une legere augmentation de la pression dans l'artere pulmonaire, sans differences entre les groupes SM et OM, mais ne provoquait pas d'hypertrophie du VD. Le taux de peroxyde d'hydrogene augmentait dans le VD des groupes MCT, mais l'activite de la SOD, de la CAT et de la GPx augmentait aussi. Les defenses anti-oxydantes non classiques diminuaient dans les groupes ovariectomises, probablement en raison d'une diminution des taux de facteur nucleaire Nrf2. L'expression proteique de l'hemoxygenase-1 et de la thioredoxine-1 augmentait davantage dans le groupe OM que dans le groupe SM, augmentation differentielle accompagnee d'une hausse des taux de recepteurs [beta] oestrogeniques (ER-[beta]). L'hemoxygenase-1 et la thioredoxine-1 pourraient jouer un role dans la modulation du stress oxydatif dans le groupe OM, phenomene qui pourrait etre responsable de l'attenuation de l'HAP et du remodelage du VD. [Traduit par la Redaction] Mots-cles : stress oxydatif, oestrogene, hemoxygenase, thioredoxine, hypertension pulmonaire., Introduction Pulmonary arterial hypertension (PAH) is characterized by an increase in mean pulmonary artery pressure (Rabinovitch 2001) due to pulmonary vascular remodelling that leads to an imbalance between excessive vasoconstrictors [...]

Infarction leads to a decrease in NO bioavailability in the erythrocytes. Thyroid hormones (TH) present positive effects after infarction. However, there are no studies evaluating the effects of cardioprotective doses of TH in the erythrocytes after infarction. This study aimed to evaluate the effects of TH in NO bioavailability and oxidative stress parameters in the erythrocytes of infarcted rats. Wistar rats were allocated into the three groups: Sham-operated (SHAM), infarcted (AMI) and infarcted + TH (AMIT). AMIT rats received T4 and T3 for 12 days by gavage. Subsequently, the animals were evaluated by echocardiography and the LV and erythrocytes were collected. TH improved NO bioavailability and increased catalase activity in the erythrocytes. Besides that, TH increased HIF-1α in the heart. TH seems to be positive for erythrocytes preventing a decrease in NO bioavailability and increasing antioxidant enzymatic defense after infarction. [ABSTRACT FROM AUTHOR]

Apoptosis is a key process associated with pathological cardiac remodelling in early-phase post-myocardial infarction. In this context, several studies have demonstrated an anti-apoptotic effect of thyroid hormones (TH). The aim of this study was to evaluate the effects of TH on the expression of proteins associated with the apoptotic process 14 days after infarction. Male Wistar rats (300-350 g) (n = 8/group) were divided into four groups: Sham-operated (SHAM), infarcted (AMI), sham-operated + TH (SHAMT) and infarcted + TH (AMIT). For 12 days, the animals received T3 and T4 [2 and 8 µg/(100 g day)] by gavage. After this, the rats were submitted to haemodynamic and echocardiographic analysis, and then were sacrificed and the heart tissue was collected for molecular analysis. Statistical analyses included two-way ANOVA with Student-Newman-Keuls post test. Ethics Committee number: 23262. TH administration prevented the loss of ventricular wall thickness and improved cardiac function in the infarcted rats 14 days after the injury. AMI rats presented an increase in the pro-apoptotic proteins p53 and JNK. The hormonal treatment prevented this increase in AMIT rats. In addition, TH administration decreased the Bax:Bcl-2 ratio in the infarcted rats. TH administration improved cardiac functional parameters, and decreased the expression of pro-apoptotic proteins 14 days after myocardial infarction. [ABSTRACT FROM AUTHOR]

Myocardial infarction leads to a reduction in nitric oxide (NO) bioavailability and an increase in reactive oxygen species (ROS) levels. This scenario has been shown to be detrimental to the heart. Recent studies have shown that thyroid hormone (TH) administration presents positive effects after ischaemic injury. Based on this, the aim of this study was to evaluate the effect of TH on NO bioavailability as well as on endothelial nitric oxide synthase (eNOS) expression after myocardial infarction. Male Wistar rats were divided into three groups: Sham-operated (SHAM), infarcted (AMI) and infarcted + TH (AMIT). During 26 days, the AMIT group received T3 and T4 (2 and 8 µg/100 g/day, respectively) by gavage, while SHAM and AMI rats received saline. After this, the rats underwent echocardiographic analysis were sacrificed, and the left ventricle was collected for biochemical and molecular analysis. Statistical analysis: one-way ANOVA with Student-Newman-Keuls post test. AMI rats presented a 38 % increase in ROS levels. TH administration prevented these alterations in AMIT rats. The AMIT group presented an increase in eNOS expression, in NOS activity and in nitrite levels. TH administration also increased PGC-1α expression in the AMIT group. In conclusion, TH effects seem to involve a modulation of eNOS expression and an improvement in NO bioavailability in the infarcted heart. [ABSTRACT FROM AUTHOR]

Introduction: Sulforaphane (SFN) is an isothiocyanate derived from glucoraphanin (GRA), which is found in great amounts especially in broccoli. Its consumption has been reported to be associated with a lower risk of myocardial infarction and cancer development. Additionally, its effects have been studied in neurodegenerative diseases, diabetes, and atherosclerosis, most of the times using animal models and cell cultures., Objectives: Given the promising results of SFN, this review aimed to investigate evidence documented in human intervention studies with broccoli, GRA and SFN., Methods: A search was performed on PubMed and Virtual Health Library databases by two independent researchers using the descriptors "broccoli" or "glucoraphanin" or "sulforaphane", which should appear on the study's title or abstract. This review included randomized clinical trials performed in humans that were published in English and Portuguese from 2003 to 2013 and that considered clinical and molecular parameters of cell damage as outcomes of interest., Results: Seventeen studies were selected, and the predominant type of intervention was broccoli sprouts. More consistent results were obtained for the clinical parameters blood glucose and lipid profile and for molecular parameters of oxidative stress, indicating that there was an improvement in these parameters after intervention. Less solid evidence was found with regard to decreased inflammation, Helicobacter pylori colonization, and protection against cancer., Conclusion: Although being relevant, the evidence for the use of broccoli, GRA and SFN in humans are limited; thus, further intervention studies are needed to evaluate outcomes more consistently and reach better grounded conclusions., (Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.)