CARLOS EDUARDO NEGRAO
Projetos de Pesquisa
Unidades Organizacionais
EFB, EEFE - Docente
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
23 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 23
- Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure(2016) ICHIGE, Marcelo H. A.; SANTOS, Carla R.; JORDAO, Camila P.; CERONI, Alexandre; NEGRAO, Carlos E.; MICHELINI, Lisete C.Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine -hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative dP/dt, decreased intrinsic heart rate (IHR), lower parasympathetic and higher sympathetic tonus, reduced preganglionic vagal neurones and ChATir in the DMV/NA, and increased RVLM DBHir. Training increased treadmill performance, normalized autonomic tonus and IHR, restored the number of DMV and NA neurones and corrected ChATir without affecting ventricular function. There were strong positive correlations between parasympathetic tonus and ChATir in NA and DMV. RVLM DBHir was also normalized by training, but there was no change in neurone number and no correlation with sympathetic tonus. Training-induced preservation of preganglionic vagal neurones is crucial to normalize parasympathetic activity and restore autonomic balance to the heart even in the persistence of cardiac dysfunction.
conferenceObject Sleep Apnea Worsens Muscle Vasoconstriction During Central and Peripheral Chemoreceptors Stimulation in Patients with Systolic Heart Failure(2016) LOBO, Denise M. L.; TREVIZAN, Patricia F.; TOSCHI-DIAS, Edgar; OLIVEIRA, Patricia A.; PIVETA, Rafael B.; MADY, Charles; BOCCHI, Edimar A.; ALMEIDA, Dirceu R.; LORENZI-FILHO, Gerald; MIDDLEKAUFF, Holly R.; NEGRAO, Carlos E.- Neurovascular Control and Cardiac Structure in Amateur Runners with Hypertension(2016) PERLINGEIRO, Patricia De Sa; AZEVEDO, Luciene Ferreira; GOMES-SANTOS, Igor Lucas; BORTOLOTTO, Luiz Aparecido; RONDON, Maria Urbana Pinto Brandao; NEGRAO, Carlos Eduardo; MATOS, Luciana Diniz Nagem Janot dePurpose The neurovascular mechanisms underlying hypertension are minimized by exercise training. However, it is not known whether previously trained individuals with hypertension would have deleterious repercussion of this disease. Our aim was to investigate the neurovascular control and the cardiac structure of athletes with hypertension. Methods Muscle sympathetic nerve activity (MSNA) (microneurography), baroreflex sensitivity (intravenous infusion of phenylephrine and nitroprusside), arterial stiffness (pulse wave velocity and echotracking), and cardiac structure (echocardiography) were evaluated in 17 runners with hypertension (42 1 yr) and 20 normotensive (43 1 yr) amateur runners. Results Runners with hypertension had higher MSNA (+24% burst frequency, P = 0.02; +24%, burst incidence, P < 0.01), left ventricular mass (+22%, P < 0.01), septum wall thickness (+9%, P = 0.04), posterior wall thickness (+11%, P = 0.04), and left atrium (+11%, P < 0.001) compared with normotensive runners. Baroreflex control of heart rate was lower in runners with hypertension during increase (P = 0.05) but not during decrease (P = 0.11) of systolic blood pressure when compared with normotensive runners. There was no difference between groups in baroreflex control of MSNA during increase (P = 0.38) and decrease (P = 0.36) of diastolic blood pressure. Pulse wave velocity (P = 0.71) and carotid variables: intima media thickness (P = 0.18), diameter (P = 0.09), and distension (P = 0.79) were similar between groups. Conclusions Sympathetic overactivity seems to be involved in the underlying mechanisms of hypertension in amateur runners. Alterations in cardiac structure and decreased baroreflex control of heart rate suggest limited protection from exercise training. However, baroreflex control of MSNA and elastic properties of artery are preserved in this population.
- Alpha2A-adrenergic receptor and eNOS genetic polymorphisms are associated with exercise muscle vasodilatation in apparently healthy individuals(2016) NUNES, Rafael Amorim Belo; BARROSO, Lucia Pereira; PEREIRA, Alexandre da Costa; RONDON, Maria Urbana Pinto Brandao; NEGRAO, Carlos Eduardo; KRIEGER, Jose Eduardo; MANSUR, Alfredo JosePurpose: Muscle vasodilatation during exercise has been associated with cardiovascular health and may be influenced by genetic variability. The purpose of this study was to evaluate functional genetic polymorphisms of physiologic pathways related to the regulation of the cardiovascular function (alpha-adrenergic receptors, endothelial nitric oxide synthase and bradykinin B2 receptor) and exercise muscle vasodilatation in apparently healthymen and women. Methods: We enrolled 689 individuals without established cardiovascular disease that had attended a check-up program. The vasodilatation was studied with venous occlusion plethysmography and determined by the increase of vascular conductance during handgrip exercise. Genotypes for ADRA1A Arg347Cys (rs1048101), ADRA2A 1780 C > T (rs553668), ADRA2B Del 301-303 (rs28365031), eNOS 786 T > C (rs2070744), eNOS Glu298Asp (rs1799983) and BDKRB2 (rs5810761) polymorphisms were assessed by polymerase chain reaction followed by high resolution melting analysis. Results: The eNOS rs2070744 polymorphism was significantly associated with forearm vascular conductance during exercise in women. Women with CC genotype showed higher vasodilatation than carriers of TC and TT genotypes (p=0.043). The ADRA2A rs553668 polymorphism was significantly associated with forearm vascular conductance during exercise inmen. Men with TT genotype had higher vasodilatation than carriers of CT and CC genotypes (p=0.025). Conclusions: eNOS rs207074 polymorphism in women and ADRA2A rs553668 polymorphism in men were associated with the increase of forearm vascular conductance during handgrip exercise. These findings suggest that eNOS and ADRA2A genetic polymorphisms may be potential markers of exercise muscle vasodilatation. (C) 2016 The Authors.
- Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients(2016) GROEHS, Raphaela V.; ANTUNES-CORREA, Ligia M.; NOBRE, Thais S.; ALVES, Maria-Janieire N. N.; RONDON, Maria Urbana P. B.; BARRETO, Antonio Carlos Pereira; NEGRAO, Carlos E.Background We investigated the effects of muscle functional electrical stimulation on muscle sympathetic nerve activity and muscle blood flow, and, in addition, exercise tolerance in hospitalised patients for stabilisation of heart failure. Methods Thirty patients hospitalised for treatment of decompensated heart failure, class IV New York Heart Association and ejection fraction30% were consecutively randomly assigned into two groups: functional electrical stimulation (n=15; 542 years) and control (n=15; 492 years). Muscle sympathetic nerve activity was directly recorded via microneurography and blood flow by venous occlusion plethysmography. Heart rate and blood pressure were evaluated on a beat-to-beat basis (Finometer), exercise tolerance by 6-minute walk test, quadriceps muscle strength by a dynamometer and quality of life by Minnesota questionnaire. Functional electrical stimulation consisted of stimulating the lower limbs at 10Hz frequency, 150ms pulse width and 70 mA intensity for 60minutes/day for 8-10 consecutive days. The control group underwent electrical stimulation at an intensity of<20 mA. Results Baseline characteristics were similar between groups, except age that was higher and C-reactive protein and forearm blood flow that were smaller in the functional electrical stimulation group. Functional electrical stimulation significantly decreased muscle sympathetic nerve activity and increased muscle blood flow and muscle strength. No changes were found in the control group. Walking distance and quality of life increased in both groups. However, these changes were greater in the functional electrical stimulation group. Conclusion Functional electrical stimulation improves muscle sympathetic nerve activity and vasoconstriction and increases exercise tolerance, muscle strength and quality of life in hospitalised heart failure patients. These findings suggest that functional electrical stimulation may be useful to hospitalised patients with decompensated chronic heart failure.
bookPart O atleta e o sistema cardiovascular(2016) OLIVEIRA, Patrícia de; ALVES, Maria Janieire Nunes; AGOSTINHO, Daniela Regina; NEGRãO, Carlos Eduardo; RODRIGUES, Amanda GonzalesbookPart Ergoespirometria(2016) AGOSTINHO, Daniela Regina; JORDãO, Camila Paixão; NEGRãO, Carlos EduardobookPart Reabilitação cardíaca(2016) ALVES, Maria Janieire Nunes; AGOSTINHO, Daniela Regina; OLIVEIRA, Patrícia Alves; NEGRãO, Carlos Eduardo; RODRIGUES, Amanda Gonzales- Increased Muscle Sympathetic Nerve Activity and Impaired Executive Performance Capacity in Obstructive Sleep Apnea(2016) GOYA, Thiago T.; SILVA, Rosyvaldo F.; GUERRA, Renan S.; LIMA, Marta F.; BARBOSA, Eline R. F.; CUNHA, Paulo Jannuzzi; LOBO, Denise M. L.; BUCHPIGUEL, Carlos A.; BUSATTO-FILHO, Geraldo; NEGRAO, Carlos E.; LORENZI-FILHO, Geraldo; UENO-PARDI, Linda M.Study Objectives: To investigate muscle sympathetic nerve activity (MSNA) response and executive performance during mental stress in obstructive sleep apnea (OSA). Methods: Individuals with no other comorbidities (age = 52 +/- 1 y, body mass index = 29 +/- 0.4, kg/m(2)) were divided into two groups: (1) control (n = 15) and (2) untreated OSA (n = 20) defined by polysomnography. Mini-Mental State of Examination (MMSE) and Inteligence quocient (IQ) were assessed. Heart rate (HR), blood pressure (BP), and MSNA (microneurography) were measured at baseline and during 3 min of the Stroop Color Word Test (SCWT). Sustained attention and inhibitory control were assessed by the number of correct answers and errors during SCWT. Results: Control and OSA groups (apnea-hypopnea index, AHI = 8 +/- 1 and 47 +/- 1 events/h, respectively) were similar in age, MMSE, and IQ. Baseline HR and BP were similar and increased similarly during SCWT in control and OSA groups. In contrast, baseline MSNA was higher in OSA compared to controls. Moreover, MSNA significantly increased in the third minute of SCWT in OSA, but remained unchanged in controls (P < 0.05). The number of correct answers was lower and the number of errors was significantly higher during the second and third minutes of SCWT in the OSA group (P < 0.05). There was a significant correlation (P < 0.01) between the number of errors in the third minute of SCWT with AHI (r = 0.59), arousal index (r = 0.55), and minimum O-2 saturation (r = -0.57). Conclusions: As compared to controls, MSNA is increased in patients with OSA at rest, and further significant MSNA increments and worse executive performance are seen during mental stress.
- Peripheral vascular reactivity and serum BDNF responses to aerobic training are impaired by the BDNF Val66Met polymorphism(2016) LEMOS JR., Jose R.; ALVES, Cleber R.; SOUZA, Silvia B. C. de; MARSIGLIA, Julia D. C.; SILVA, Michelle S. M.; PEREIRA, Alexandre C.; TEIXEIRA, Antnio L.; VIEIRA, Erica L. M.; KRIEGER, Jose E.; NEGRAO, Carlos E.; ALVES, Guilherme B.; OLIVEIRA, Edilamar M. de; BOLANI, Wladimir; DIAS, Rodrigo G.; TROMBETTA, Ivani C.Besides neuronal plasticity, the neurotrophin brain-derived neurotrophic factor (BDNF) is also important in vascular function. The BDNF has been associated with angiogenesis through its specific receptor tropomyosin-related kinase B (TrkB). Additionally, Val66Met polymorphism decreases activity-induced BDNF. Since BDNF and TrkB are expressed in vascular endothelial cells and aerobic exercise training can increase serum BDNF, this study aimed to test the hypotheses: 1) Serum BDNF levels modulate peripheral blood flow; 2) The Val66Met BDNF polymorphism impairs exercise training-induced vasodilation. We genotyped 304 healthy male volunteers (Val66Val, n = 221; Val66Met, n = 83) who underwent intense aerobic exercise training on a running track three times/wk for 4 mo. We evaluated pre- and post-exercise training serum BDNF and proBDNF concentration, heart rate (HR), mean blood pressure (MBP), forearm blood flow (FBF), and forearm vascular resistance (FVR). In the pre-exercise training, BDNF, proBDNF, BDNF/proBDNF ratio, FBF, and FVR were similar between genotypes. After exercise training, functional capacity ((v)over dot(O2) (peak)) increased and HR decreased similarly in both groups. Val66Val, but not Val66Met, increased BDNF (interaction, P = 0.04) and BDNF/proBDNF ratio (interaction, P < 0.001). Interestingly, FBF (interaction, P = 0.04) and the FVR (interaction, P = 0.01) responses during handgrip exercise (HG) improved in Val66Val compared with Val66Met, even with similar responses of HR and MBP. There were association between BDNF/proBDNF ratio and FBF (r = 0.64, P < 0.001) and FVR (r = -0.58,P < 0.001) during HG exercise. These results show that peripheral vascular reactivity and serum BDNF responses to exercise training are impaired by the BDNF Val66Met polymorphism and such responsiveness is associated with serum BDNF concentrations in healthy subjects.
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