Publications by authors named "Hiviny de Ataides Raquel"

3 Publications

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Swimming training reduces iNOS expression, augments the antioxidant defense and reduces sympathetic responsiveness in the rostral ventrolateral medulla of normotensive male rats.

Brain Res Bull 2021 May 23;170:225-233. Epub 2021 Feb 23.

Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil. Electronic address:

We sought to investigate whether RVLM iNOS activity and oxidative profile may participate in the reduction of sympathetic responsiveness in swimming trained normotensive rats. Sedentary (S) and swimming trained (T) Wistar male rats chronically instrumented with an arterial catheter and guide cannula into the RVLM were submitted to continuous pressure and heart rate (HR) recordings and determination of autonomic control (power spectral analysis) before and after unilateral RVLM iNOS inhibition (aminoguanidine, 250 pmol/100 nL). Other S and T rats received local l-glutamate microinjection (5 nmol/100 nL). In separate S and T groups not submitted to brainstem cannulation, fresh bilateral RVLM punchs were collected for iNOS gene expression (qPCR); reduced glutathione and lipid peroxidation quantification (spectrophotometry); iron-reducing antioxidant (FRAP) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS˙) scavenger assays. iNOS gene expression was confirmed in fixed RVLM slices (immunofluorescence). T rats exhibited resting bradycardia, lower sympathovagal balance, reduced RVLM iNOS gene/protein expression and higher antioxidant capacity. Decreased iNOS expression was positively correlated with reduced HR. Pressor and tachycardic response to l-Glutamate were smaller in T rats. Aminoguanidine microinjection reduced sympathetic activity in S rats but did not change it in T rats expressing reduced RVLM iNOS content. Our data indicate that iNOS, expressed in the RVLM of normotensive male rats, has tonic effects on sympathetic activity and that swimming training is an efficient tool to reduce iNOS expression and augment the antioxidant defense, thus reducing glutamatergic responsiveness and sympathetic drive to cardiovascular effectors.
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http://dx.doi.org/10.1016/j.brainresbull.2021.02.023DOI Listing
May 2021

The essential role of hypothalamic paraventricular nucleus nNOS in the modulation of autonomic control in exercised rats.

Nitric Oxide 2018 09 3;79:14-24. Epub 2018 Jul 3.

Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil. Electronic address:

Nitric oxide (NO), an intercellular signaling molecule is relevant for circulatory autonomic control. Brain NO synthase (NOS) and NO levels were downregulated in pathological conditions, but rescued after exercise training. We hypothesized that exercise training was also able to improve NO modulation within the hypothalamic paraventricular nucleus (PVN) of healthy rats. Male Wistar rats were submitted to two 4-weeks protocols: i) swimming training (T) or kept sedentary (S), ii) l-arginine (62,5 mg/mL, 1 mL/day p. o.) or vehicle supplementation. Rats underwent stereotaxic surgery (PVN bilateral guide cannulas) and chronic catheterization of artery/vein. Arterial pressure (AP), heart rate (HR) and baroreflex sensitivity were recorded in conscious rats at rest and following a selective nNOS inhibitor (Nw-Propyl-l-Arginine, 4 nmol/100 nL) within the PVN. Rats were deeply anesthetized for brain perfusion/harvesting after respiratory arrest. In separate groups (T and S, l-arginine and Vehicle supplemented) not submitted to PVN cannulation, fresh and fixed brains were obtained for gene and protein nNOS expression (qPCR and immunohistochemistry) and nitrite levels (Griess reaction). T and l-arginine treatment were accompanied by resting bradycardia, augmented parasympathetic and reduced sympathetic activity to heart and vessels (power spectral analysis) and increased baroreflex sensitivity (P < 0.05). In contrast, PVN nNOS inhibition blocked/attenuated these effects in addition to significantly increase in resting MAP and HR (with larger effects in T and l-arginine treated rats vs. respective controls, P < 0.05). T increased nNOS gene and protein expression within the ventromedial and posterior PVN nuclei (P < 0.05). PVN nitirite levels were also increased in T and l-arginine groups (P < 0.05). Data strongly suggest that training by increasing NO availability within PVN preautonomic nuclei favors both the slow down of sympathetic and the augmentation of parasympathetic activity and facilitates baroreflex control, therefore improving autonomic regulation of the heart in healthy rats.
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http://dx.doi.org/10.1016/j.niox.2018.07.002DOI Listing
September 2018

Moderate Treadmill Exercise Training Improves Cardiovascular and Nitrergic Response and Resistance to Infection in Mice.

Front Physiol 2017 18;8:315. Epub 2017 May 18.

Department of Physiological Sciences, Center of Biological Sciences, State University of LondrinaLondrina, Brazil.

There is evidence suggesting that exercise training (ET) acts as a factor toward resistance to infection. However, the effects of mean arterial pressure (MAP), heart rate (HR), and nitric oxide (NO) during the acute phase of infection has not been elucidated yet. Swiss mice were randomly assigned into four groups: sedentary control (SC, = 30), trained control (TC, = 30), sedentary infected (SI, = 30), and trained infected (TI, = 30). ET was performed on the treadmill for 9 weeks. After training, the mice were infected with 5 × 10 trypomastigotes of (Y strain) or PBS. We observed resting bradycardia and improved performance in trained animals compared with sedentary ones. On the 20th day post-infection (DPI), we found a decrease in HR in SI animals compared to TI animals (699.73 ± 42.37 vs. 742.11 ± 25.35 bpm, respectively, < 0.05). We also observed increased production of NO in cardiac tissue on the 20th DPI in the SI group, normalized in TI group (20.73 ± 2.74 vs. 6.51 ± 1.19 μM, respectively). Plasma pro-inflammatory cytokines (IL-12, TNF-α, IFN-γ,) and MCP-1 were increased in SI animals, but decreased in TI animals. The increase in parasitemia on the 15th and 17th DPI in the SI group was attenuated in the TI group. Our results suggest that previous ET plays a preventive role in resistance to infection, modulating cardiovascular aspects, inflammatory reaction, and NO levels of infected mice.
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http://dx.doi.org/10.3389/fphys.2017.00315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5435761PMC
May 2017