944 resultados para CARDIOVASCULAR SYSTEM


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No clear evidence is available in the literature regarding the acute effect of different styles of music on cardiac autonomic control. The present study aimed to evaluate the acute effects of classical baroque and heavy metal musical auditory stimulation on Heart Rate Variability (HRV) in healthy men. In this study, HRV was analyzed regarding time (SDNN, RMSSD, NN50, and pNN50) and frequency domain (LF, HF, and LF / HF) in 12 healthy men. HRV was recorded at seated rest for 10 minutes. Subsequently, the participants were exposed to classical baroque or heavy metal music for five minutes through an earphone at seated rest. After exposure to the first song, they remained at rest for five minutes and they were again exposed to classical baroque or heavy metal music. The music sequence was random for each individual. Standard statistical methods were used for calculation of means and standard deviations. Besides, ANOVA and Friedman test were used for parametric and non-parametric distributions, respectively. While listening to heavy metal music, SDNN was reduced compared to the baseline (P = 0.023). In addition, the LF index (ms(2) and nu) was reduced during exposure to both heavy metal and classical baroque musical auditory stimulation compared to the control condition (P = 0.010 and P = 0.048, respectively). However, the HF index (ms(2)) was reduced only during auditory stimulation with music heavy metal (P = 0.01). The LF/HF ratio on the other hand decreased during auditory stimulation with classical baroque music (P = 0.019). Acute auditory stimulation with the selected heavy metal musical auditory stimulation decreased the sympathetic and parasympathetic modulation on the heart, while exposure to a selected classical baroque music reduced sympathetic regulation on the heart.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Objective: To review the cardiovascular consequences of obstructive sleep-disordered breathing in children Data source: Medline and Ovid data base. Study selection: pediatric articles (original articles and case report) that investigated the obstructive sleep-disordered breathing in children Data synthesis: The obstructive sleep-disordered breathing can lead to serious cardiovascular consequences such as pulmonary hypertension, pulmonary edema and anatomic and functional abnormalities Conclusions: The knowledge of cardiovascular repercussions allows in better management of pediatric patients and may result in positive consequences for treatment and follow up of these patients.

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The ageing process can change the pharmacodynamics and pharmacokinetics parameters. Therefore, some medications are considered potentially inappropriate (PIM) for the elderly people, since they can increase the likelihood of occurrence of adverse drug events. The objectives are to estimate the frequency of use of PIM in the elderly people, with potentially hazardous drug interactions (PHDI) and to evaluate the impact of pharmaceutical intervention (PI) for the prescription of safer therapeutic alternatives. A cross-sectional study was performed in a Health Family Strategy (region of Araraquara, SP), between January and February/2012. The medical records of patients aged ≥60 years, that use at least one drug, were consulted for identification of PIM, according to the Beers criteria. The MPI identified were classified considering the Anatomical Therapeutic Chemical Classification System (ATC) and the essentiality of the drug (safety, effectiveness, quality and cost parameters) The inclusion criteria were met by 358 elderly, being that 93 of them (26%) had taken at least one PIM. Of the 114 different drugs prescribed for elderly, ten were classified as PIM, of which four of them act on the central nervous system, four on cardiovascular system and two on the digestive tract. Seven MPI are essential medicines, belonging to national list of essential drugs (RENAME-2010). Fourteen drug interactions were identified, of which two are PHDI (fluoxetine/amitriptyline and digoxin/hydrochlorothiazide).After the PI, there was no change in medical prescriptions of patients with PIM use or with DI. Medical prescriptions of elderly attended in the Health Family Strategy show pharmacotherapeutic safety problems, of which may be responsible for health hazardous for this age group. Although the intervention carried out by letter had been ineffective for the adherence of doctors in prescribing safe alternatives, wide dissemination of the lists that contain PIM and PHDI is need, as well as the inclusion of safer equivalents in RENAME, in order to contribute for rational use of drugs.

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You can set the resistance training such as making a move against a resistance by performing a muscle contraction and generating a muscular adaptation. This form of training, was initially used only in training athletes aiming to strengthen and improve fitness. Some coaches did not give proper focus, as the increase in muscle mass would cause loss of flexibility and agility. But over time a huge evolution occurred within this area and the practitioners of resistance training are no longer just athletes, and reached the whole community, from young to elderly, being a physical activity that generates a large caloric expenditure and has several health benefits, improve the cardiovascular system and decreasing the amount of body fat in the body. Cortisol is a hormone secreted from a stressful stimulus to the body, secretion undergoes control of the hypothalamic-pituitary axis, which releases the hormone into the bloodstream andrenocorticotrópico, going to the adrenal cortex responsible for their release. This has catabolic function, acting in the metabolism of carbohydrates, proteins and lipids, as well as having an important effect antiflamatório. Testosterone is a steroid hormone cholesterol from being produced by the testicles in men, as in women is produced to a lesser extent in ovary and adrenal glands, has functions androgenic and anabolic. Androgen function is responsible for the development of male sexual characteristics, while on anabolic function operates in the growth of muscles and bones, influencing the development of the human body organs. Within the metabolic changes that occur in the resistance training testosterone plays an important role in protein synthesis, influencing the production of strength and / or power during exercise. The objective of this work is through a literature review to assess the effects of resistance training on the production of these hormones and the relationship between them

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The neural control of the cardiovascular system is a complex process that involves many structures at different levels of nervous system. Several cortical areas are involved in the control of systemic blood pressure, such as the sensorimotor cortex, the medial prefrontal cortex and the insular cortex. Non-invasive brain stimulation techniques - repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) - induce sustained and prolonged functional changes of the human cerebral cortex. rTMS and tDCS has led to positive results in the treatment of some neurological and psychiatric disorders. Because experiments in animals show that cortical modulation can be an effective method to regulate the cardiovascular system, non-invasive brain stimulation might be a novel tool in the therapeutics of human arterial hypertension. We here review the experimental evidence that non-invasive brain stimulation can influence the autonomic nervous system and discuss the hypothesis that focal modulation of cortical excitability by rTMS or tDCS can influence sympathetic outflow and, eventually, blood pressure, thus providing a novel therapeutic tool for human arterial hypertension. (C) 2009 Published by Elsevier Ltd.

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Nitric oxide (NO), produced by endothelial nitric oxide synthase (eNOS), is a potent vasodilator and plays a prominent role in regulating the cardiovascular system. Decreased basal NO release may predispose to cardiovascular diseases. Evidence suggests that the 27 nt repeat polymorphism of the intron 4 in the eNOS gene may regulate eNOS expression. On the other hand, some recent reports strongly suggest an association between methylmercury (MeHg) exposures and altered NO synthesis. In the present study, we investigate the contribution of the 27-pb tandem repeat polymorphism on nitric oxide production, which could enhance susceptibility to cardiovascular disease in the MeHg-exposed study population. Two-hundred-two participants (98 men and 104 women), all chronically exposed to MeHg through fish consumption were examined. Mean blood Hg concentration and nitrite plasma concentration were 50.5 +/- 35.4 mu g/L and 251.4 +/- 106.3 nM, respectively. Mean systolic and diastolic blood pressure were 120.1 +/- 19.4 mm Hg and 72.0 +/- 10.6 mm Hg, respectively. Mean body mass index was 24.5 +/- 4.3 kg/m(2) and the mean heart rate was 69.8 +/- 11.8 bpm. There were no significant differences in age, arterial blood pressure, body mass index or cardiac frequency between genotype groups (all P>0.05). However, we observed different nitrite concentrations in the genotypes groups, with lower nitrite levels for the 4a4a genotype carriers. Age, gender and the presence of intron 4 polymorphism contributed to nitrite reduction as a result of blood Hg concentration. Taken together, our results show that the 27 nt repeat polymorphism of the intron 4 in the eNOS gene increases susceptibility to cardiovascular diseases after MeHg exposure by modulating nitric oxide levels. (C) 2011 Elsevier B.V. All rights reserved.

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Smoking crack cocaine involves the inhalation of cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). Although there is evidence that cocaine is neurotoxic, the neurotoxicity of AEME has never been evaluated. AEME seems to have cholinergic agonist properties in the cardiovascular system; however, there are no reports on its effects in the central nervous system. The aim of this study was to investigate the neurotoxicity of AEME and its possible cholinergic effects in rat primary hippocampal cell cultures that were exposed to different concentrations of AEME, cocaine, and a cocaineAEME combination. We also evaluated the involvement of muscarinic cholinergic receptors in the neuronal death induced by these treatments using concomitant incubation of the cells with atropine. Neuronal injury was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The results of the viability assays showed that AEME is a neurotoxic agent that has greater neurotoxic potential than cocaine after 24 and 48 h of exposure. We also showed that incubation for 48 h with a combination of both compounds in equipotent concentrations had an additive neurotoxic effect. Although both substances decreased cell viability in the MTT assay, only cocaine increased LDH release. Caspase-3 activity was increased after 3 and 6 h of incubation with 1mM cocaine and after 6 h of 0.1 and 1.0mM AEME exposure. Atropine prevented the AEME-induced neurotoxicity, which suggests that muscarinic cholinergic receptors are involved in AEME's effects. In addition, binding experiments confirmed that AEME has an affinity for muscarinic cholinergic receptors. Nevertheless, atropine was not able to prevent the neurotoxicity produced by cocaine and the cocaineAEME combination, suggesting that these treatments activated other neuronal death pathways. Our results suggest a higher risk for neurotoxicity after smoking crack cocaine than after cocaine use alone.

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Angiotensin II (All), the active component of the renin angiotensin system (RAS), plays a vital role in the regulation of physiological processes of the cardiovascular system, but also has autocrine and paracrine actions in various tissues and organs. Many studies have shown the existence of RAS in the pancreas of humans and rodents. The aim of this study was to evaluate potential signaling pathways mediated by All in isolated pancreatic islets of rats. Phosphorylation of MAPKs (ERK1/2, JNK and p38MAPK), and the interaction between proteins JAK/STAT were evaluated. All increased JAK2/STAT1 (42%) and JAK2/STAT3 (100%) interaction without altering the total content of JAK2. Analyzing the activation of MAPKs (ERK1/2, JNK and p38MAPK) in isolated pancreatic islets from rats we observed that All rapidly (3 min) promoted a significant increase in the phosphorylation degree of these proteins after incubation with the hormone. Curiously JNK protein phosphorylation was inhibited by DPI, suggesting the involvement of NAD(P)H oxidase in the activation of protein. (C) 2012 Elsevier B.V. All rights reserved.

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In the present study, we investigated the involvement of beta-adrenoceptors in the medial amygdaloid nucleus (MeA) in cardiovascular responses evoked in rats submitted to an acute restraint stress. We first pretreated Wistar rats with the nonselective beta-adrenoceptor antagonist propranolol microinjected bilaterally into the MeA (10, 15, and 20 nmol/100 nL) 10 min before exposure to acute restraint. The pretreatment with propranolol did not affect the blood pressure (BP) increase evoked by restraint. However, it increased the tachycardiac response caused by acute restraint when animals were pretreated with a dose of 15 nmol, without a significant effect on the BP response. This result indicates that beta-adrenoceptors in the MeA have an inhibitory influence on restraint-evoked heart rate (HR) changes. Pretreatment with the selective beta(2)-adrenoceptor antagonist ICI 118,551 (10, 15, and 20 nmol/100 nL) significantly increased the restraint-evoked tachycardiac response after doses of 15 and 20 nmol, an effect that was similar to that observed after the pretreatment with propranolol at a dose of 15 nmol, without a significant effect on the BP response. Pretreatment of the MeA with the selective beta(1)-adrenoceptor antagonist CGP 20712 (10, 15, and 20 nmol/100 nL) caused an opposite effect on the HR response, and a significant decrease in the restraint-evoked tachycardia was observed only after the dose of 20 nmol, without a significant effect on the BP response. Because propranolol is an equipotent antagonist of both beta(1) and beta(2)-adrenoceptors, and opposite effects were observed after the treatment with the higher doses of the selective antagonists ICI 118,551 and CGP 20712, the narrow window in the dose-response to propranolol could be explained by a functional antagonism resulting from the simultaneous inhibition of beta(1) and beta(2)-adrenoceptors by the treatment with propranolol. The present results suggest that beta(2)-adrenoceptors have an inhibitory influence on the restraint-evoked tachycardiac response, whereas beta(1)-adrenoceptors have a facilitatory influence on the restraint-evoked tachycardiac response. (c) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

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Aims: Metformin is an insulin sensitizing agent with beneficial effects in diabetic patients on glycemic levels and in the cardiovascular system. We examined whether the metabolic changes and the vascular dysfunction in monosodium glutamate-induced obese non-diabetic (MSG) rats might be improved by metformin. Main methods: 16 week-old MSG rats were treated with metformin for 15 days and compared with age-matched untreated MSG and non-obese non-diabetic rats (control). Blood pressure, insulin sensitivity, vascular reactivity and prostanoid release in the perfused mesenteric arteriolar bed as well as nitric oxide production and reactive oxygen species generation in isolated mesenteric arteries were analyzed. Key findings: 18-week-old MSG rats displayed higher Lee index, fat accumulation, dyslipidemia, insulin resistance and hyperinsulinemia. Metformin treatment improved these alterations. The norepinephrine-induced response, increased in the mesenteric arteriolar bed from MSG rats, was corrected by metformin. Indomethacin corrected the enhanced contractile response in MSG rats but did not affect metformin effects. The sensitivity to acetylcholine, reduced in MSG rats, was also corrected by metformin. Indomethacin corrected the reduced sensitivity to acetylcholine in MSG rats but did not affect metformin effects. The sensitivity to sodium nitroprusside was increased in preparations from metformin-treated rats. Metformin treatment restored both the reduced PGI2/TXA2 ratio and the increased reactive oxygen species generation in preparations from MSG rats. Significance: Metformin improved the vascular function in MSG rats through reduction in reactive oxygen species generation, modulation of membrane hyperpolarization. correction of the unbalanced prostanoids release and increase in the sensitivity of the smooth muscle to nitric oxide. (c) 2011 Elsevier Inc. All rights reserved.