BRUNO RODRIGUES
Projetos de Pesquisa
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- Ventricular and autonomic benefits of exercise training persist after detraining in infarcted rats(2013) BARBOZA, Catarina Andrade; ROCHA, Leandro Yanase; MOSTARDA, Cristiano Teixeira; FIGUEROA, Diego; CAPERUTO, Erico Chagas; ANGELIS, Katia De; IRIGOYEN, Maria Claudia; RODRIGUES, BrunoWe evaluate the effects of detraining (DT, for 1 month) on the left ventricular (LV) remodeling and function, hemodynamic and baroreflex sensitivity (BRS), as well as on mortality rate of infarcted (MI) rats after 3 months of exercise training (ET, 50-70 % of VO2max). Male Wistar rats were divided into five groups: control (C, n = 10), untrained-infarcted (UI, n = 15), trained-infarcted (TI, n = 12), untrained-infarcted plus 1 month (UI-1, n = 15) and detrained-infarcted 1 month (DI-1, n = 15). LV function was evaluated by echocardiography at the initial and final of the protocols. After following, ET and/or DT protocols, hemodynamic and BRS [by tachycardic (TR) and bradycardic (BR) responses] were assessed. TI group displayed increased VO2max in comparison with UI and DI-1 groups; however, DI-1 values remained increased compared to UI-1 group. MI area was reduced by ET and maintained after DT. Ejection fraction (TI = 60 +/- A 2 and DI-1 = 61 +/- A 2 % vs. UI = 41 +/- A 1 and UI-1 = 37 +/- A 3 %), E/A ratio (TI = 1.6 +/- A 0.1 and DI-1 = 1.9 +/- A 0.1 vs. UI = 2.9 +/- A 0.2 and UI-1 = 2.9 +/- A 0.3), TR (TI = 3.3 +/- A 0.3 and DI-1 = 3.3 +/- A 0.4 vs. UI = 1.7 +/- A 0.1 and UI-1 = 1.6 +/- A 0.1 bpm/mmHg) and BR (TI = -2.2 +/- A 0.1 and DI-1 = -2.0 +/- A 0.1 vs. UI = -1.3 +/- A 0.09 and UI-1 = -1.2 +/- A 0.09 bpm/mmHg) were improved by ET and maintained after DT in comparison with untrained rats. These changes resulted in mortality reduction in the TI (8 %) and DI-1 groups (13 %) compared with the UI (46 %) and UI-1 (53 %) groups. These findings indicate that ET is not only an effective tool in the management of cardiovascular and autonomic MI derangements, but also that these positive changes were maintained even after 1 month of DT in rats.
- Cholinergic stimulation with pyridostigmine improves autonomic function in infarcted rats(2013) FUENTE, Raquel N. de La; RODRIGUES, Bruno; MORAES-SILVA, Ivana C.; SOUZA, Leandro E.; SIRVENTE, Raquel; MOSTARDA, Cristiano; ANGELIS, Katia De; SOARES, Pedro P.; LACCHINI, Silvia; CONSOLIM-COLOMBO, Fernanda; IRIGOYEN, Maria-Claudia1. In the present study we evaluated the effects of shortterm pyridostigmine bromide (0.14 mg/mL) treatment started early after myocardial infarction (MI) on left ventricular (LV) and autonomic functions in rats. 2. Male Wistar rats were divided into control, pyridostigmine, infarcted and infarcted + pyridostigmine-treated groups. Pyridostigmine was administered in the drinking water, starting immediately after MI or sham operation, for 11 days. Left ventricular function was evaluated indirectly by echocardiography and directly by LV catheterization. Cardiovascular autonomic control was evaluated by baroreflex sensitivity (BRS), heart rate variability (HRV) and pharmacological blockade. All evaluations started after 7 days pyridostigmine treatment and were finalized after 11 days treatment. 3. Pyridostigmine prevented the impairment of + dP/dT and reduced the MI area in infarcted + pyridostigmine compared with infarcted rats (7 +/- 3% vs 17 +/- 4%, respectively). Mean blood pressure was restored in infarcted + pyridostigmine compared with infarcted rats (103 +/- 3 vs 94 +/- 3 mmHg, respectively). In addition, compared with the infarcted group, pyridostigmine improved BRS, as evaluated by tachycardic (1.6 +/- 0.2 vs 2.5 +/- 0.2 b. p. m./mmHg, respectively) and bradycardic (-0.42 +/- 0.01 vs -1.9 +/- 0.1 b. p. m./mmHg) responses, and reduced the low frequency/high frequency ratio of HRV (0.81 +/- 0.11 vs 0.24 +/- 0.14, respectively). These improvements are probably associated with increased vagal tone and reduced sympathetic tone in infarcted + pyridostigmine compared with infarcted rats. 4. In conclusion, the data suggest that short-term pyridostigmine treatment started early after MI can improve BRS, HRV and parasympathetic and sympathetic tone in experimental rats. These data may have potential clinical implications because autonomic markers have prognostic significance after MI.
- Can High Altitude Influence Cytokines and Sleep?(2013) LEMOS, Valdir de Aquino; SANTOS, Ronaldo Vagner Thomatieli dos; LIRA, Fabio Santos; RODRIGUES, Bruno; TUFIK, Sergio; MELLO, Marco Tulio deThe number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O-2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1 beta), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.
- Impact of myocardial infarction on cardiac autonomic function in diabetic rats(2013) RODRIGUES, Bruno; MOSTARDA, Cristiano T.; JORGE, Luciana; BARBOZA, Catarina A.; GRANS, Camilla F.; ANGELIS, Katia De; IRIGOYEN, Maria ClaudiaAims: We evaluated autonomic and hemodynamic parameters and maximal oxygen consumption (VO(2)max) as possible determinants of mortality in streptozotocin (STZ) diabetic rats after myocardial infarction (MI). Method: Male Wistar rats were divided into (n=8 of each): control sham (CS), diabetes sham (DS), MI (I), and diabetes +MI (DI). MI was induced 15 days after STZ induction. VO(2)max was measured at 3 (basal), 30, 60, and 91 days after MI. Hemodynamic and autonomic parameters were evaluated 92 days after MI. Results: MI area was similar in infarcted groups (similar to 44%). Mortality rate increased in the DI (70%) compared with I (53%) group. Cardiopulmonary baroreflex, sympathetic (48%) and vagal (33%) tonus, low frequency (LF) band (57%), and LF/high frequency (HF) band ratio (53%) were reduced in DI compared with I animals. Furthermore, cardiac output (CO), peripheral vascular resistance (PVR) impairment, and VO(2)max reductions were observed in the DI compared with the I group. Conclusions: Our data suggest that the CO and PVR changes as well as VO(2)max reduction were probably associated with additional cardiac autonomic control impairment, and, consequently, increased mortality rate in diabetic rats after a chronic myocardial infarction.