Evolution of oxidative stress biomarkers and correlation with competitive performance in two moments of the swimming training season

Estudos têm demonstrado aumento na formação de espécies reativas de oxigênio após o esforço físico intenso. Esses eventos podem aumentar a suscetibilidade das células musculares a danos oxidativos como a peroxidação lipídica. Assim, variações na intensidade e no volume de treinamento durante a temporada podem modular o metabolismo oxidativo e influenciar a performance dos atletas. OBJETIVO: Estudar a evolução de biomarcadores de peroxidação lipídica em dois momentos de um ciclo periodizado de treinamento e relacionar com a performance competitiva de natação. MÉTODOS: Participaram do presente estudo 16 nadadores (nove do gênero masculino e sete do feminino). Amostras de sangue foram coletadas em dois períodos do ciclo de treinamento: período preparatório específico e período de polimento. Espécies reativas ao ácido tiobarbitúrico (TBARS) e peróxidos totais foram determinados como biomarcadores de peroxidação lípidica. Creatina quinase foi determinada como parâmetro de dano celular muscular. O índice técnico alcançado no estilo de especialidade de cada atleta foi utilizado como parâmetro de performance competitiva. O índice técnico foi determinado na competição preparatória Troféu Electro Bonini realizada no período preparatório específico, e no Campeonato Paulista realizado no final do período de polimento. RESULTADOS: Foi encontrado aumento significativo (p < 0,05) no índice técnico no Campeonato Paulista (769,6 ± 51,1 pontos) em relação ao Troféu Electro Bonini (751,1 ± 55,7 pontos). Significativas reduções na concentração de TBARS (5,7 ± 2,9 vs 3,3 ± 2,2µmol/L) e peróxidos totais (45,1 ± 20,6 vs 29,6 ± 13,0, µmol H2O2/L) foram encontrados no período de polimento com relação ao período preparatório específico. O mesmo não foi encontrado para creatina quinase (123,6 ± 60,1 vs 137,4 ± 74,9U/L). CONCLUSÃO: A significativa diminuição nos biomarcadores de peroxidação lipídica decorrente do decréscimo no volume e intensidade do treinamento após o período de polimento demonstra a influência das variações do treinamento sobre o estresse oxidativo e sua possível relação com a performance.INTRODUCTION: Studies have shown increase in the formation of oxygen reactive species after intense physical exertion. These events may increase the susceptibility of muscular cells to oxidative damage such as lipid per-oxidation. Thus, variations in training intensity as well as volume during the season may modulate the oxidative stress and influence in performance of athletes. AIM: To study the evolution of lipid peroxidation biomarkers in two moments of a periodized cycle of training and correlate it with swimming competitive performance. METHODS: 16 swimmers participated in this study (9 males and 7 females). Blood samples were collected in two periods of the training cycle: specific preparation training and tapering period. Species reactive to thiobarbituric acid (TBARS) and total peroxides were determined as lipid peroxidation biomarkers. Creatine kinase was determined as a parameter of muscular cell damage. The technical index reached in the style of specialization of each athlete was used as a competitive performance parameter. The technical index was determined in the preparatory competition Trophy Electro Bonini carried out in the specific preparatory period and in the Championship of São Paulo State carried out in the end of the tapering period (769.6 ± 51.1 points) in comparison with the Trophy Electro Bonini (751.1 ± 55.7 points). Significant reductions In the TBARS concentration ((5.7 ± 2.9 vs 3.3 ± 2.2µmol/L) and total peroxides (45.1±20.6 vs 29.6±13.0 µmol H2O2/L) were found In the tapering period concerning the specific preparatory period. The same situation was not found for creatine kinase ((123.6 ± 60.1 vs 137.4 ± 74.9U/L). CONCLUSION: The significant decrease in the biomarkers of lipid peroxidation derived from the decrease in the volume and intensity of training after the tapering training demonstrates the influence of the training variations on the oxidative stress and its possible relation with performance.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

SUPLEMENTAÇÃO DE CREATINA, HOMOCISTEÍNA E ESTRESSE OXIDATIVO

Creatine is a popular substance among athletes due its possible ergogenic property. Such popularity has been stimulating authors to study and explore the possible potencial therapeutic effect of this substance. The synthesis of creatine is responsible for the majority methyl groups transferences in the normal hepatic metabolism. As homocysteine is an aminoacid formed exclusively from the methionine demetilation, it is believed that creatine and homocysteine are metabolically connected. Studies have show that hyperhomocysteinemia is directly linked to oxygen reactive species formation by the homocysteine and/or cysteine auto-oxidation and this can promote cellular damage. The aim of this review is to discuss some aspects of creatine supplementation on homocysteine levels and oxidative stress.A creatina é uma substância popular entre atletas devido a sua possível propriedade ergogênica. Tal popularidade incentivou autores a estudar e explorar o possível potencial terapêutico desta substância. A síntese de creatina é responsável pela maioria das transferências de grupos metila no metabolismo hepático normal. Como a homocisteína é um aminoácido formado exclusivamente a partir da desmetilação da metionina, acredita-se que a creatina e homocisteína estejam metabolicamente conectadas. Estudos têm mostrado que a hiperhomocisteinemia está diretamente ligada à formação de espécies reativas de oxigênio pela autooxida ção da homocisteína e/ou da cisteína e que tal auto-oxidação pode provocar danos celulares. O objetivo desta revisão é discutir aspectos da suplementação com creatina relacionados aos níveis de homocisteína e o estresse oxidativo

Effects of vitamin C supplementation on acute phase Chagas disease in experimentally infected mice with Trypanosoma cruzi QM1 strain

The tissue changes that occur in Chagas disease are related to the degree of oxidative stress and antioxidant capacity of affected tissue. Studies with vitamin C supplementation did not develop oxidative damage caused by Chagas disease in the host, but other studies cite the use of peroxiredoxins ascorbate - dependent on T. cruzi to offer protection against immune reaction. Based on these propositions, thirty "Swiss" mice were infected with T. cruzi QM1 strain and treated with two different vitamin C doses in order to study the parasitemia evolution, histopathological changes and lipid peroxidation biomarkers during the acute phase of Chagas disease. The results showed that the parasite clearance was greater in animals fed with vitamin C overdose. There were no significant differences regarding the biomarkers of lipid peroxidation and inflammatory process or the increase of myocardium in animals treated with the recommended dosage. The largest amount of parasite growth towards the end of the acute phase suggests the benefit of high doses of vitamin C for trypomastigotes. The supplementation doesn't influence the production of free radicals or the number of amastigote nests in the acute phase of Chagas disease.As alterações teciduais que ocorrem na doença de Chagas estão relacionadas ao grau de estresse oxidativo e à capacidade antioxidante do tecido afetado. Estudos realizados com suplementação de vitamina C revelaram redução no dano oxidativo causado no hospedeiro pela doença de Chagas, porém outros estudos citam o uso de peroxiredoxinas dependentes de ascorbato pelo T. cruzi para se proteger da ação imune. Com base nessas proposições, trinta camundongos "Swiss" foram infectados com a cepa QM1 de T. cruzi e tratados com duas diferentes doses de vitamina C para estudar a evolução da parasitemia, alterações histopatológicas e dosagem de biomarcadores de peroxidação lipídica durante a fase aguda da doença de Chagas. Os resultados mostraram que a parasitemia foi maior nos animais que receberam uma superdosagem de vitamina C. Não houve diferenças significativas quanto aos biomarcadores de peroxidação lipídica e houve maior processo inflamatório no miocárdio dos animais tratados com dosagem recomendada. O maior crescimento parasitário ao fim da fase aguda sugere benefício de altas doses de vitamina C aos tripomastigotas. A suplementação não exerceu influência sobre a produção de radicais livres e o número de ninhos de amastigotas na fase aguda da doença de Chagas

Age-dependent changes in rat lacrimal gland anti-oxidant and vesicular related protein expression profiles

Anti-oxidation and exocytosis are important for maintaining exocrine tissue homeostasis. During aging, functional and structural alterations occur in the lacrimal gland (LG), including oxidative damage to proteins, lipids, and DNA. The aims of the present study were to determine in the aging LG: a) the effects of aging on LG structure and secretory activity and b) changes in the expression of oxidative stress markers.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Effects of ovariectomy and resistance training on oxidative stress markers in the rat liver

OBJECTIVE: The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats. METHOD: Adult Sprague-Dawley rats were divided into the following four groups (n = 8 per group): sham-operated sedentary, ovariectomized sedentary, sham-operated resistance training, and ovariectomized resistance training. During the resistance training period, the animals climbed a 1.1-m vertical ladder with weights attached to their tails; the sessions were conducted 3 times per week, with 4-9 climbs and 8-12 dynamic movements per climb. The oxidative stress was assessed by measuring the levels of reduced glutathione and oxidized glutathione, the enzymatic activity of catalase and superoxide dismutase, lipid peroxidation, vitamin E concentrations, and the gene expression of glutathione peroxidase. RESULTS: The results showed significant reductions in the reduced glutathione/oxidized glutathione ratio (4.11±0.65 nmol/g tec), vitamin E concentration (55.36±11.11 nmol/g), and gene expression of glutathione peroxidase (0.49±0.16 arbitrary units) in the livers of ovariectomized rats compared with the livers of unovariectomized animals (5.71±0.71 nmol/g tec, 100.14±10.99 nmol/g, and 1.09±0.54 arbitrary units, respectively). Moreover, resistance training for 10 weeks was not able to reduce the oxidative stress in the livers of ovariectomized rats and induced negative changes in the hepatic anti-oxidative/oxidative balance. CONCLUSION: Our findings indicate that the resistance training program used in this study was not able to attenuate the hepatic oxidative damage caused by ovariectomy and increased the hepatic oxidative stress

Efecto de la suplementación de creatina sobre marcadores de daño muscular y desempeño físico en atletas de voleibo

Given creatine supplementation may attenuate exer-cise-induced damage and directly influence the ATP-CP system, the purpose of the study is to assess the effects of creatine (Cr) supplementation on muscle damage markers; creatine kinase (CK) and lactate dehydrogena-se (LDH), late-onset muscle pain (DOMS) and physical performance in volleyball athletes. A controlled study with a double blind model was performed. Fourteen participants supplemented (0.3 g / kg) of creatine or placebo during (loading phase) and (0.1 g / kg) during (maintenance phase). Significant differences were ob-served in total plasma creatine concentration (p <0.05), body weight (p = 0.047) and lower pain perception (p = 0.020), 24 hours (p = 0.001), 48 hours (p <0.001) and 72 hours (p = 0.011) in the creatine group. The evaluation of subjective perception of pain verified a significant difference in the creatine group (p <0.05). It was con-cluded that creatine supplementation, associated with carbohydrate consumption, attenuated the perception of pain in volleyball players after the muscle damage protocol.Dado que la suplementación con creatina puede atenuar el daño inducido por el ejercicio e influir directamente en el sistema ATP-CP, el propósito del estudio es evaluar los efectos de la suplementación con creatina (Cr) sobre los marcadores de daño muscular como; creatina quinasa (CK) y lactato deshidrogenasa (LDH), dolor muscular de aparición tardía (DOMS) y rendimiento físico en atletas de voleibol. Se realizó un estudio controlado con modelo doble ciego. Catorce participantes suplementaron (0.3 g / kg) de creatina o placebo durante (fase de carga) y (0.1 g / kg) durante (fase de mantenimiento). Diferencias significativas fueron observadas en la concentración plasmática total de creatina (p <0.05), peso corporal (p = 0.047) y menor percepción del dolor (p = 0.020), 24 horas (p = 0.001), 48 horas (p <0.001 ) y 72 horas (p = 0.011) en el grupo creatina. La evaluación de la percepción subjetiva del dolor verificó diferencia significativa en el grupo creatina (p <0.05). Se concluyó que la suplementación de creatina, asociada al consumo de carbohidratos atenuó la percepción de dolor en los jugadores de voleibol después del protocolo de daño muscular.Actividad Física y Deport

Supervised, but Not Home-Based, Isometric Training Improves Brachial and Central Blood Pressure in Medicated Hypertensive Patients: A Randomized Controlled Trial

Meta-analyses have shown that supervised isometric handgrip training reduces blood pressure in hypertensives. However, the mechanism(s) underlying these effects in medicated hypertensive patients, as well as the effects from home-based exercise training, is uncertain. The purpose of this study was to compare the effects of supervised and home-based isometric handgrip training on cardiovascular parameters in medicated hypertensives. In this randomized controlled trial, 72 hypertensive individuals (38–79 years old, 70% female) were randomly assigned to three groups: home-based, supervised isometric handgrip training or control groups. Home-based and supervised isometric handgrip training was completed thrice weekly (4 × 2 min at 30% of maximal voluntary contraction, with 1-min rest between bouts, alternating the hands). Before and after 12 weeks brachial, central and ambulatory blood pressures (BP), arterial stiffness, heart rate variability, vascular function, oxidative stress and inflammation markers were obtained. No significant (p &gt; 0.05) effect was observed for ambulatory BP, arterial stiffness, heart rate variability, vascular function and oxidative stress and inflammatory markers in all three groups. Brachial BP decreased in the supervised group (Systolic: 132 ± 4 vs. 120 ± 3 mmHg; Diastolic: 71 ± 2 vs. 66 ± 2 mmHg, p &lt; 0.05), whereas no significant differences were observed in the home-based (Systolic: 130 ± 4 vs. 126 ± 3 mmHg; diastolic: 73 ± 3 vs. 71 ± 3 mmHg) and control groups (p &gt; 0.05). Supervised handgrip exercise also reduced central BP systolic (120 ± 5 vs. 109 ± 5 mmHg), diastolic (73 ± 2 vs. 67 ± 2 mmHg); and mean BP (93 ± 3 vs. 84 ± 3 mmHg), whereas no significant effects were found in the home-based (Systolic: 119 ± 4 vs. 115 ± 3 mmHg; Diastolic: 74 ± 3 vs. 71 ± 3 mmHg) and control groups (p &gt; 0.05). In conclusion, supervised, but not home-based, isometric training lowered brachial and central BP in hypertensives