Viviane L. A. Nouailhetas
Federal University of São Paulo
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Featured researches published by Viviane L. A. Nouailhetas.
Journal of Applied Physiology | 2009
Eloi F. Rosa; Rafael Ferreira Ribeiro; Felipe M. T. Pereira; Edna Freymüller; Jeannine Aboulafia; Viviane L. A. Nouailhetas
Intense and exhaustive exercise (IEE) is associated with oxidative stress in skeletal muscle, and we recently reported that intestine is sensitive to IEE. In the present study, we investigated the possible relationship between the effects of IEE on morphology and oxidative markers in the ileum and isolated mitochondria. C57BL/6 mice were ascribed either to a control group comprising two subgroups, one sedentary and another exercised for 10 days (E10), or to a corresponding supplemented control group again comprising two subgroups, one sedentary and another exercised for 10 days (E10-V). The IEE program consisted of a single daily treadmill running session at 85% of V(max), until animal exhaustion. Vitamins C (10 mg/kg) and E (10 mg/kg) were concurrently intraperitoneally administered 2 h before the exercise sessions. IEE was shown to cause 1) impairment of ileum internal membrane mitochondria verified by ultramicrography analysis; 2) increase in ileum carbonyl content (117%) and reduction in antioxidant capacity (36%); 3) increase in mitochondria carbonyl content (38%), increase in the percentage of ruptured mitochondria (25.3%), increase in superoxide dismutase activity (186%), and reduction in citrate synthase activity (40.4%) compared with control animals. Observations in the vitamin-supplemented exercised animals (E10-V) were 1) healthy appearance of myocyte mitochondria; 2) decrease in ileum carbonyl content (66%) and increase in antioxidant capacity (53%); 3) decrease in mitochondria carbonyl content (43%), decrease in the percentage of ruptured mitochondria (30%), slight increase in superoxide dismutase activity (7%), and significant increase in citrate synthase activity (121%) compared with E10 animals. Therefore, the present results strongly corroborate the hypothesis that IEE leads to marked disturbances in intestinal mitochondria, mainly in redox status, and affects whole intestinal redox status.
Journal of Applied Physiology | 2008
Eloi F. Rosa; Edna Freymüller; Silvia Saiuli Miki Ihara; Jeannine Aboulafia; Viviane L. A. Nouailhetas
Several gastrointestinal symptoms associated with prolonged intense exercise (IE) have been reported, although the mechanisms underlying its effects on the intestine remain poorly understood. The aim of the present study was to investigate whether IE may induce oxidative stress in the intestine, as well as its possible relationship with intestinal signaling impairments, leading to contractile disturbances. C57BL/6 mice were submitted to 4 days (EX.4D) and 10 days (EX.10D) of IE. The daily exercise session consisted of a running session until exhaustion, with the treadmill speed set at 85% of each animals maximum velocity. The decrease in exhaustion time was exponential, and the reduction in the maximum velocity, as assessed by an incremental test, was higher in EX.4D than in EX.10D animals. The ileum mucosa layer was partially destroyed after 4 days of IE, where 37% and 11% muscle layer atrophies were observed in EX.4D and EX.10D animals, respectively. Ileum contractility was significantly impaired in the EX.4D animal group, with reduced efficacy for carbachol, bradykinin, and KCl signaling associated with a decrease in lipid peroxidation and with no alteration of protein oxidation. Intestinal myocytes from EX.10D animals displayed areas containing structurally disorganized mitochondria, which were associated with increased levels of protein oxidation, without alteration of contractility, except for a reduction in the potency of bradykinin signaling. Finally, no clear relationship between ileum contractility and oxidative stress was shown. Together, these results argue in favor of significant functional, biochemical, and morphological disturbances caused by exercise, thus demonstrating that intestinal tissue is very sensitive to exercise.
European Journal of Pharmacology | 1985
Viviane L. A. Nouailhetas; Suma I. Shimuta; Antonio C. M. Paiva; Therezinha B. Paiva
The isometric responses of the longitudinal smooth muscle of the guinea-pig ileum to acetylcholine and to histamine consist of a phasic contraction followed by a fade and a tonic contraction. At high agonist concentrations the fade is more pronounced and a period of lower tonus is observed in the early stage of the tonic component of the response. Experiments done in Ca2+-free medium indicate that the events responsible for the shape of the response take place in the absence of Ca2+ and of contraction. The phasic contraction was inhibited by hyperpolarization in low-Na+ medium. Small decreases in the external Na+ concentration caused a diminution of the fade. Reduction of the Na+ concentration during the early stages of the tonic response caused contraction whereas relaxation was observed at the late stages. It is proposed that the fade is dependent on a Na+-sensitive mechanism that is predominant at early but not at late stages of the responses to agonists.
Clinics | 2010
Carolina Ackel-D'Elia; Rodrigo Luiz Vancini; Adauto Castelo; Viviane L. A. Nouailhetas; Antonio Carlos da Silva
OBJECTIVE: The aim of this study was to evaluate the occurrence of the well‐known predisposing factors and signs and symptoms usually associated with either overreaching or overtraining syndrome in physical fitness centers in São Paulo City, Brazil. METHOD: A questionnaire consisting of 13 question groups pertaining to either predisposing factors (1‐7) or signs and symptoms (8‐13) was given to 413 subjects. The general training schedule of the volunteers was characterized by workout sessions of 2.18 ± 0.04 h for a total of 11.0 ± 0.3 h/week for 33 ± 2 months independent of the type of exercise performed (walking, running, spinning, bodybuilding and stretching). A mean score was calculated ranging from 1 (completely absent) to 5 (severe) for each question group. A low occurrence was considered to be a question group score lower than 4, which was observed in all 13 question groups. RESULTS: The psychological evaluation by POMS Mood State Questionnaire indicated a normal non‐inverted iceberg. The hematological parameters, creatine kinase activity, cortisol, total testosterone and free testosterone concentrations were within the normal ranges for the majority of the volunteers selected for this analysis (n = 60). CONCLUSION: According to the questionnaire score analysis, no predisposing factors or signs and symptoms usually associated with either overreaching or overtraining were detected among the members of physical fitness centers in São Paulo City, Brazil. This observation was corroborated by the absence of any significant hematological or stress hormone level alterations in blood analyses of the majority of the selected volunteers (n = 60).
American Journal of Physiology-cell Physiology | 1998
Fernando Romero; Bagnólia A. Silva; Viviane L. A. Nouailhetas; Jeannine Aboulafia
We investigated the regulation of the Ca(2+)-activated K+ (maxi-K+) channel by angiotensin II (ANG II) and its synthetic analog, [Lys2]ANG II, in freshly dispersed intestinal myocytes. We identified a maxi-K+ channel population in the inside-out patch configuration on the basis of its conductance (257 +/- 4 pS in symmetrical 150 mM KCl solution), voltage and Ca2+ dependence of channel opening, low Na(+)-to-K+ and Cl(-)-to-K+ permeability ratios, and blockade by external Cs+ and tetraethylammonium chloride. ANG II and [Lys2]ANG II caused an indirect, reversible, Ca(2+)- and dose-dependent activation of maxi-K+ channels in cell-attached experiments when cells were bathed in high-K+ solution. This effect was reversibly blocked by DUP-753, being that it is mediated by the AT1 receptor. Evidences that activation of the maxi-K+ channel by ANG II requires a rise in intracellular Ca2+ concentration ([Ca2+]i) as an intermediate step were the shift of the open probability of the channel-membrane potential relationship to less positive membrane potentials and the sustained increase in [Ca2+]i in fura 2-loaded myocytes. The preservation of the pharmacomechanical coupling of ANG II in these cells provides a good model for the study of transmembrane signaling responses to ANG II and analogs in this tissue.We investigated the regulation of the Ca2+-activated K+(maxi-K+) channel by angiotensin II (ANG II) and its synthetic analog, [Lys2]ANG II, in freshly dispersed intestinal myocytes. We identified a maxi-K+ channel population in the inside-out patch configuration on the basis of its conductance (257 ± 4 pS in symmetrical 150 mM KCl solution), voltage and Ca2+ dependence of channel opening, low Na+-to-K+and Cl--to-K+permeability ratios, and blockade by external Cs+ and tetraethylammonium chloride. ANG II and [Lys2]ANG II caused an indirect, reversible, Ca2+- and dose-dependent activation of maxi-K+ channels in cell-attached experiments when cells were bathed in high-K+ solution. This effect was reversibly blocked by DUP-753, being that it is mediated by the AT1 receptor. Evidences that activation of the maxi-K+ channel by ANG II requires a rise in intracellular Ca2+concentration ([Ca2+]i) as an intermediate step were the shift of the open probability of the channel-membrane potential relationship to less positive membrane potentials and the sustained increase in [Ca2+]iin fura 2-loaded myocytes. The preservation of the pharmacomechanical coupling of ANG II in these cells provides a good model for the study of transmembrane signaling responses to ANG II and analogs in this tissue.
Journal of Orthopaedic Research | 2011
Alberto de Castro Pochini; Benno Ejnisman; Maria Teresa de Seixas Alves; Luiz Fernando Uyeda; Viviane L. A. Nouailhetas; Sang Won Han; Moisés Cohen; Walter Manna Albertoni
The presence of mechanoreceptors in tendon after overuse activities can be a further step to learn about tendinopathy and overuse. Studies of tendons mechanoreceptors in rats are rare. We studied 12 isogenic spontaneous hypertensive rats (SHR), which underwent an overuse protocol consisting of an hour per daily session of treadmill running at a speed of 17 m/min, 5 times/week for 4 months. Supraspinatus tendons were evaluated with immunohistochemistry using S100 protein antibodies and histological protocol. Supraspinatus tendons at the end of 4 months of overuse protocol had a high number of media mechanoreceptors (4.3) than controls (0.6). The overexpression of S100 protein antibody in overuse activities maybe could represent a adaptative effort to tendon before the tear.
American Journal of Physiology-gastrointestinal and Liver Physiology | 2014
Gabriel Andrade Alves; Luísa Ribeiro Silva; Eloi F. Rosa; Jeannine Aboulafia; Edna Freymüller-Haapalainen; Caden Souccar; Viviane L. A. Nouailhetas
Protein dystrophin is a component of the dystrophin-associated protein complex, which links the contractile machinery to the plasma membrane and to the extracellular matrix. Its absence leads to a condition known as Duchenne muscular dystrophy (DMD), a disease characterized by progressive skeletal muscle degeneration, motor disability, and early death. In mdx mice, the most common DMD animal model, loss of muscle cells is observed, but the overall disease alterations are less intense than in DMD patients. Alterations in gastrointestinal tissues from DMD patients and mdx mice are not yet completely understood. Thus, we investigated the possible relationships between morphological (light and electron microscopy) and contractile function (by recording the isometric contractile response) with alterations in Ca²⁺ handling in the ileum of mdx mice. We evidenced a 27% reduction in the ileal muscular layer thickness, a partial damage to the mucosal layer, and a partial damage to mitochondria of the intestinal myocytes. Functionally, the ileum from mdx presented an enhanced responsiveness during stretch, a mild impairment in both the electromechanical and pharmacomechanical signaling associated with altered calcium influx-induced contraction, with no alterations in the sarcoplasmic reticulum Ca²⁺ storage (maintenance of the caffeine and thapsigargin-induced contraction) compared with control animals. Thus, it is evidenced that the protein dystrophin plays an important role in the preservation of both the microstructure and ultrastructure of mice intestine, while exerting a minor but important role concerning the intestinal contractile responsiveness and calcium handling.
Natural Product Research | 2015
Ana Carolina de Carvalho Correia; Tamyris F. Ferreira; Italo R.R. Martins; Cibério Landim Macêdo; Fabio de S. Monteiro; Vicente Carlos de Oliveira Costa; Josean Fechine Tavares; Marcelo Sobral da Silva; Edgar J. Paredes-Gamero; Marcus V. Buri; Vera L.S. Rigoni; Viviane L. A. Nouailhetas; Bagnólia Araújo da Silva
Xylopia langsdorfiana A. St.-Hil. &Tul. (Annonaceae) is popularly known in the northeast of Brazil as ‘pimenteira da terra’, and an essential oil (XL-OE) was extracted from its leaves. Since Xylopia species are cited in folk medicine and diterpenes from X. langsdorfiana have spasmolytic activity, this study aimed to investigate a possible spasmolytic action of XL-OE on smooth muscle models. XL-OE (243 and 729 μg/mL) showed low pharmacologic efficacy on guinea pig trachea and rat aorta and uterus. However, in guinea pig ileum, XL-OE (27–729 μg/mL) inhibited carbachol or histamine-induced phasic contractions (1 μM) in a significant and concentration-dependent manner. In addition, XL-OE (81 μg/mL) reduced fluorescence intensity in ileal myocytes stimulated by histamine, indicating a decrease in cytosolic calcium concentration, which could explain the spasmolytic activity. Thus, XL-OE proved to be a promising natural product to be used in gastrointestinal diseases acting by modulating the cytosolic calcium concentration.
European Journal of Pharmacology | 2012
Rosimeire F. dos Santos; Italo R.R. Martins; Rafael de Almeida Travassos; Josean Fechine Tavares; Marcelo Sobral da Silva; Edgar J. Paredes-Gamero; Alice T. Ferreira; Viviane L. A. Nouailhetas; Jeannine Aboulafia; Vera L.S. Rigoni; Bagnólia Araújo da Silva
In this study we investigated the mechanism underlying the spasmolytic action of ent-7α-acetoxytrachyloban-18-oic acid (trachylobane-360) and ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318), diterpenes obtained from Xylopia langsdorfiana, on guinea pig ileum. Both compounds inhibited histamine-induced cumulative contractions (slope=3.5±0.9 and 4.4±0.7) that suggests a noncompetitive antagonism to histaminergic receptors. CaCl(2)-induced contractions were nonparallelly and concentration-dependently reduced by both diterpenes, indicating blockade of calcium influx through voltage-dependent calcium channels (Ca(v)). The Ca(v) participation was confirmed since both trachylobanes equipotently relaxed ileum pre-contracted with S-(-)-Bay K8644 (EC(50)=3.5±0.7×10-(5) and 1.1±0.2×10-(5)M) and KCl (EC(50)=5.5±0.3×10-(5) and 1.4±0.2×10-(5)M). K(+) channels participation was confirmed since diterpene-induced relaxation curves were significantly shifted to right in the presence of 5mM tetraethylammonium (TEA(+)) (EC(50)=0.5±0.04×10-(4) and 2.0±0.5×10-(5)M). ATP-sensitive K(+) channel (K(ATP)), voltage activated K(+) channels (K(V)), small conductance calcium-activated K(+) channels (SK(Ca)) or big conductance calcium-activated K(+) channels (BK(Ca)) did not seem to participate of trachylobane-360 spasmolytic action. However trachylobane-318 modulated positively K(ATP), K(V) and SK(Ca) (EC(50)=1.1±0.3×10-(5), 0.7±0.2×10-(5) and 0.7±0.2×10-(5)M), but not BK(Ca). A fluorescence analysis technique confirmed the decrease of cytosolic calcium concentration ([Ca(2+)](c)) induced by both trachylobanes in ileal myocytes. In conclusion, trachylobane-360 and trachylobane-318 induced spasmolytic activity by K(+) channel positive modulation and Ca(2+) channel blockade, which results in [Ca(2+)](c) reduction at cellular level leading to smooth muscle relaxation.
American Journal of Physiology-cell Physiology | 1999
Bagnólia A. Silva; Viviane L. A. Nouailhetas; Jeannine Aboulafia
Desensitization of ANG II tonic contractile response of the guinea pig ileum is related to membrane repolarization determined by Ca2+-activated K+(maxi-K+) channel opening. ANG II-stimulated depolarized myocytes presented sustained activation of maxi-K+ channels, characterized by reduction from 415 to 12 ms of the closed time constant. ANG II desensitization was prevented by 100 nM iberiotoxin, being reversible within 30 min. Depolarization by KCl, higher than 4 mM, impaired desensitization, suggesting that the membrane potential must attain a threshold to counteract the repolarization induced by maxi-K+ channel opening. Once this value is attained, there is no time dependency because the desensitization process was shut off by addition of KCl along the time course of the tonic response. In contrast, the sustained ACh tonic component was not altered by these maneuvers. We conclude that desensitization of the ANG II tonic component is foremost due to the opening of maxi-K+ channels, leading to membrane repolarization, thus closing the voltage-dependent Ca2+ channels responsible for the Ca2+ influx that sustains the tonic component in this muscle.