THE EFFECT OF INTERMITTENT HYPOXIC TRAINING UNDER OXIDATIVE STRESS PARAMETERS IN WISTAR RATS FED ON STANDARD AND HIGH FAT DIET

Considerando-se que dietas ricas em gordura levam ao estresse oxidativo, causando lesões nas células e que o treinamento hipóxico intermitente (THI) aumenta as defesas antioxidantes endógenas em diversas situações, o objetivo deste estudo foi avaliar o efeito do THI em parâmetros de estresse oxidativo e defesas antioxidantes em fígado de ratos Wistar alimentados com dieta rica em gordura e/ou dieta padrão. Ratos Wistar foram divididos em grupos alimentados com dieta padrão ou rica em gordura. Os grupos foram submetidos a hipóxia intermitente (HI), 15 minutos HI (14-11% O2) intercalados com cinco minutos de re-oxigenação ou sessões de normóxia (N) (21% O2), por um período de duas horas diárias durante 30 dias. Os ratos Wistar alimentados com dieta padrão, e submetidas a HI, apresentaram uma redução de 37,7% na concentração de substâncias reativas ao ácido tiobarbitúrico (TBARS) e aumento de 34,66% e 39,8% no conteúdo de superóxido dismutase (SOD) e catalase (CAT), respectivamente, em comparação com o seu controlo (normoxia). No grupo com dieta rica em gordura, não houve diferença estatística entre os subgrupos HI e N. Nossos dados, que demonstram que o THI possui efeito antioxidante no fígado de ratos Wistar, argumentam em favor do uso alternativo de protocolos de hipoxia intermitente no tratamento de determinadas patologias

Redox profile in liver of Leporinus macrocephalus exposed to different dissolved oxygen levels

Aquatic organisms are continuously exposed to environmental variations, which can lead to physiological and biochemical alterations. Leporinus macrocephalus, known as piavuçu, is a migratory species that may be exposed to variations in dissolved oxygen levels. Studies evaluating oxidative changes undergone by this species in these conditions are scarce. Therefore, this investigation aimed at evaluating oxidative alterations in L. macrocephalus exposed to different oxygen levels for 96 h: 6. 12 ± 0. 18, 3. 99 ± 0. 17, 3. 22 ± 0. 17, 2. 47 ± 0. 30 and 0. 710 ± 0. 07 mg L -1. At the end of the experimental period, fish were euthanized and livers used to determine lipid hydroperoxides, thiobarbituric acid reactive substances, catalase, glutathione-S-transferase, superoxide dismutase and thiol groups, which are an indirect measure of reduced glutathione. Results indicated a decrease in the studied parameters in hypoxic situations, suggesting a possible metabolic depression. © 2011 Springer Science+Business Media B.V.Fil: Riffel, A. P. K.. Universidade Federal de Santa Maria; BrasilFil: Garcia, L. O.. Universidade Federal de Santa Maria; Brasil. Universidade Federal do Rio Grande do Norte; BrasilFil: Finamor, I. A.. Universidade Federal de Santa Maria; BrasilFil: Saccol, E.M.H.. Universidade Federal de Santa Maria; BrasilFil: Meira, M.. Universidade Federal de Santa Maria; BrasilFil: Kolberg, C.. Universidade Federal do Rio Grande do Sul; BrasilFil: Horst, A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Partata, W.. Universidade Federal do Rio Grande do Sul; BrasilFil: Llesuy, Susana Francisca. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Baldisserotto, B.. Universidade Federal de Santa Maria; BrasilFil: Pavanato, M. A.. Universidade Federal de Santa Maria; Brasi

T2-weighted BOLD in human myocardium

The principal aim of this work is to test the viability of Blood Oxygenation Level Dependent (BOLD) measurements in human myocardium, an experiment which has seen promising attempts in recent literature. A central challenge to the ~uccess of these experiments has been in the limited scale of the measured effect; this work therefore includes efforts to separate the BOLD effect from noise and confounding signals. BOLD is then measured by intensity in MR images produced using Steady State Free Precession (SSFP) acquisition, weighted by a T2 preparation module to introduce the target contrast. Two modelling sections are included: first, the changes in physiology which influence the signal intensity in the MR images via the T2 dependence; and secondly the factors upon which the preparation depends, which are not entirely limited to the T2 of the tissue. These models are investigated with the aim of increasing the BOLD contrast and removing any other dependencies. An empirical model is shown to be suitable for the relationship between oxygenation and T2, and improvements are suggested and explained by thorough simulation ofthe preparation module. Compensation for a further confounding effect is also investigated: that of the increase in heart rate which accompanies the adenosine infusion used in the BOLD experiment protocol to reveal differences in the response of ischaemic and healthy tissue. The compensation is shown to reduce temporal variance in SI measurements, and to increase the separation between distributions of SI in tissue classes. A process of registration and segmentation is refined for sampling BOLD information from the SS FP images, and tested to show a low failure rate. Finally, the BOLD process is then tested in a set of human subjects including healthy volunteers and patients with coronary artery disease, investigating the consequent difference in tissue oxygenation. A significant difference is shown in the responses to stress of BOLD SI three tissue classes in these subjects.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Efecto de la adición de aceite esencial de Myrcia sylvatica (G. Mey.) DC (AEMS) en la dieta de dorada (Sparus aurata) bajo situaciones de estrés crónico producido por densidad

Trabajo presentado en el XV Congreso Nacional de Acuicultura y el I Congreso Ibérico de Acuicultura, celebrados en Huelva del 13 al 16 de octubre de 2015.[ES] Unas condiciones de cultivo inadecuadas (por ejemplo la alta densidad), causan estrés a los peces, afectando el metabolismo de lípidos, hidratos de carbono y proteínas. El objetivo de este estudio fue evaluar los efectos de la adición de aceite esencial de Myrcia sylvatica (AEMS) en la dieta de ejemplares de Sparus aurata en situaciones de baja y alta densidad. Los juveniles de dorada fueron distribuidos y alimentados con tres dietas experimentales durante tres meses: i) control, ii) 1,0 mL AEMS/kg de pienso, y iii) 2.0 mL AEMS/kg de pienso. Transcurrido este tiempo, cada grupo experimental fue dividido en dos nuevas condiciones: baja y alta densidad de carga (BD, 5 kg/m3 y AD, 40 kg/m3, respectivamente) para tener un total de seis grupos experimentales: i) control-BD, ii) control-AD, iii) 1,0 mL-BD, iv) 1,0 mL-AD, v) 2,0 mL-BD, y vi) 2,0 mL-AD). Después de 22 días bajo estas condiciones, 10 individuos de cada tratamiento fueron anestesiados y se extrajeron muestras de sangre e hígado para el análisis de cortisol y metabolitos. Nuestros resultados muestran que la adición de AEMS disminuye los niveles de cortisol en condiciones de BD y AD. Además, se observa que dietas suplementadas con dosis cercanas a 2,0 mL AEMS/kg de pienso originan una reorganización metabólica para poder afrontar la situación de estrés producido por la alta densidad de carga.[EN] Inadequate stocking densities (e.g. high stocking density) activated stress system, affecting the metabolism of lipids, carbohydrates and proteins. The aim of this study was to evaluate the effects of adding essential oil of Myrcia sylvatica (EOMS) in the diet of Sparus aurata juveniles held at different stocking densities. Juvenile specimens were distributed into the three experimental groups, feeding three different diets during three additional months: i) control, ii) 1.0 mL EOMS/kg of feed, and iii) 2.0 mL EOMS/kg feed. After that, each experimental group was divided in two different conditions: low and high stocking densities (LD-5 kg/m3 and HD-40 kg/m3, respectively) constituting a total of six different treatments: i) control-LD, ii) control-HD, iii) 1.0 mL-LD, iv) 1.0 mL-HD, v) 2.0 mL-LD, and vi) 2.0 mL-HD). After 22 days under these conditions, 10 individuals from each treatment were anesthetized and sampled for plasma and liver. These samples were analysed for cortisol and metabolites analysis. Our results shown that EOMS decreased plasma cortisol levels under LD and HD conditions. Moreover, it is observed that diets supplemented with 2.0 mL EOMS/kg of food originates a metabolic reorganization to cope with the stressful situation produced by higher stocking densities.Etiane M. H. Saccol y Y.A. Parrado-Sanabria contaron con el apoyo de becas de doctorado y máster de la Comisión de Formación de Personal de Nivel Superior (CAPES) y a la Asociación Universitaria Iberoamericana de Postgrado (AUIP), respectivamente. Este trabajo ha sido financiado por el proyecto AGL2013-48835-C2-1-R (MINECO, España) concedido a J.M. Mancera.N

Evaluación de la adición de aceite esencial de Myrcia sylvatica (G. Mey.) DC (AEMS) en la dieta y su efecto sobre el crecimiento y fisiología de la dorada (Sparus aurata)

Trabajo presentado en el XV Congreso Nacional y el I Congreso Ibérico de Acuicultura (Acuicultura, cultivando el futuro), celebrado en Huelva del 13 al 16 de octubre de 2015.[ES] Las actividades acuícolas producen situaciones de estrés que disminuyen el bienestar de los peces cultivados. El objetivo de este estudio fue evaluar los efectos de la adición del aceite esencial de Myrcia sylvatica (AEMS), una sustancia que mitiga la activación del sistema de estrés en otras especies de teleósteos, en la dieta de la dorada (Sparus aurata). Los juveniles de dorada fueron proporcionados por los Servicios Centrales de Investigación de Cultivos Marinos (SCI-CM, Universidad de Cádiz), aclimatados durante un mes en tanques de 1000 L y distribuidos en 9 tanques de 80 L (densidad de carga inicial: 2,76 ± 0,013 g/L) que constituyeron los tres grupos experimentales por triplicado: i) control, ii) 1,0 mL AEMS/kg de pienso, y iii) 2,0 mL AEMS/kg de pienso. Tras 90 días, los peces (n = 9 por grupo experimental) fueron anestesiados, medidos y pesados. Posteriormente, se extrajeron muestras de sangre e hígado para el análisis de cortisol y metabolitos. La adición en la dieta de AEMS disminuyó los niveles de cortisol y triglicéridos en plasma, así como del glucógeno hepático. Por tanto, nuestros resultados sugieren que la adición de AEMS en la dieta (dosis entre 1,0-2,0 mL AEMS/kg de pienso) podría mejorar el bienestar animal de esta especie durante su cultivo.[EN] Aquaculture activities promote stress situations that decrease fish welfare. In this sense, the objective of this study was to evaluate the effects of adding essential oil of Myrcia sylvatica (EOMS), a substance that has been used to mitigate activation of stress system in other teleost, in the diet of gilthead sea bream (Sparus aurata). Juveniles specimens were provided by the Servicios Centrales de Investigación de Cultivos Marinos (SCI-CM, University of Cadiz), acclimated for one month in 1000 L-tanks and distributed in 9 tanks of 80 L (initial stocking density: 2.76 ± 0.013 g/L), which constituted the three experimental groups in triplicate: i) control, ii) 1.0 mL EOMS/kg food, and iii) 2.0 mL EOMS/kg food). After 90 days, fish (n = 9 fish per group) were anesthetized measured and weighed. Subsequently, blood and liver samples were extracted for cortisol and metabolites analysis. The addition of EOMS in diet decreased plasma cortisol levels and plasma triglycerides, as well as liver glycogen. Therefore, our results suggest that the addition of EOMS in the diet (doses between 1.0-2.0 mL EOMS/kg food) could promote fish welfare of this specie in culture.Este trabajo ha sido financiado por el proyecto AGL2013-48835-C2-1-R (MINECO, España) concedido a J.M.M.N

The Protective Effect of N-Acetylcysteine on Oxidative Stress in the Brain Caused by the Long-Term Intake of Aspartame by Rats

Long-term intake of aspartame at the acceptable daily dose causes oxidative stress in rodent brain mainly due to the dysregulation of glutathione (GSH) homeostasis. N-Acetylcysteine provides the cysteine that is required for the production of GSH, being effective in treating disorders associated with oxidative stress. We investigated the effects of N-acetylcysteine treatment (150 mg kg(-1), i.p.) on oxidative stress biomarkers in rat brain after chronic aspartame administration by gavage (40 mg kg(-1)). N-Acetylcysteine led to a reduction in the thiobarbituric acid reactive substances, lipid hydroperoxides, and carbonyl protein levels, which were increased due to aspartame administration. N-Acetylcysteine also resulted in an elevation of superoxide dismutase, glutathione peroxidase, glutathione reductase activities, as well as non-protein thiols, and total reactive antioxidant potential levels, which were decreased after aspartame exposure. However, N-acetylcysteine was unable to reduce serum glucose levels, which were increased as a result of aspartame administration. Furthermore, catalase and glutathione S-transferase, whose activities were reduced due to aspartame treatment, remained decreased even after N-acetylcysteine exposure. In conclusion, N-acetylcysteine treatment may exert a protective effect against the oxidative damage in the brain, which was caused by the long-term consumption of the acceptable daily dose of aspartame by rats.Fil: Finamor, Isabela A.. Universidade Federal de Santa Maria; BrasilFil: Ourique, Giovana M.. Universidade Federal de Santa Maria; BrasilFil: Pês, Tanise S.. Universidade Federal de Santa Maria; BrasilFil: Saccol, Etiane M. H.. Universidade Federal de Santa Maria; BrasilFil: Bressan, Caroline A.. Universidade Federal de Santa Maria; BrasilFil: Scheid, Taína. Universidade Federal do Rio Grande do Sul; BrasilFil: Baldisserotto, Bernardo. Universidade Federal de Santa Maria; BrasilFil: Llesuy, Susana Francisca. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Partata, Wânia A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Pavanato, Maria A.. Universidade Federal do Rio Grande do Sul; Brasi

Oxidative stress parameters in juvenile Brazilian flounder Paralichthys orbignyanus (Valenciennes, 1839) (Pleuronectiformes: Paralichthyidae) exposed to cold and heat shocks

The aim of this study was to determine oxidative stress parameters in the liver and gill of Brazilian flounder juveniles (307.0 ± 16.0 g and 30.0 ± 4.0 cm) submitted to different water temperature (17.1, 23.0 and 28.8ºC) for 72 h and maintained at salinity 25‰. After the acclimation of 7 days, in 23ºC, fish were transferred to 200 L tanks containing seawater (salinity 25‰) at 28.8ºC (heat shock), 17.1ºC (cold shock) or 23.0ºC (control), five replicates (five fish tank-1). The sampled collection occurred in 0 (pre-challenge), 3, 24, 48 and 72 h after temperature shock. Flounder exposed to 17.1ºC and 28.8ºC showed significantly higher TBARS levels and GST activity in the liver post-exposition (PE) in relation to the control (23ºC). CAT activity in liver present a significantly increase at 17.1ºC, in first 48 h, and subsequently decrease in 72 h PE in relation to 28.8ºC. The gills of flounder showed significantly higher TBARS levels, GST and CAT activity when submitted at 17.1 and 28.8ºC in relation to 23.0ºC. There were observed changes in lipid peroxidation levels (LPO), CAT and GST activities in the liver and gill of Brazilian flounder in response to reactive oxygen species (ROS) produced by thermal shocks

Myrcia sylvatica essential oil in the diet of gilthead sea bream (Sparus aurata L.) attenuates the stress response induced by high stocking density

The effects of diet supplemented with Myrcia sylvatica essential oil (EOMS) on growth and stress tolerance to different stocking densities were assessed in Sparus aurata. Initially, three experimental groups were established: (i) control, (ii) 1.0 and (iii) 2.0 ml EOMS/kg dry feed. After 90 days, nine fish per group were anaesthetized, weighed and sampled for metabolic analysis. The remaining fish were divided into two different conditions: low (LD—5 kg/m3) and high (HD—40 kg/m3) stocking densities, constituting a final experimental setup with six treatments. After 22 days, 10 individuals per treatment were anaesthetized and sampled for biochemical analysis. EOMS feeding for 90 days did not interfere with growth, although it was effective in reducing cortisol levels and the activation of lipid and carbohydrate metabolism. The HD interfered in growth performance, increased the lactate levels in the control group, reducing also hepatic glycogen levels without dependence on diet supplementation. The 2.0 ml EOMS + LD group increased the growth parameters and decreased the cortisol and triglycerides levels. Additionally, metabolism adjustment was observed to provide energy during LD and HD conditions, indicating that diets supplemented with EOMS produce metabolic reorganization to maintain body homeostasis, suggesting its use as a beneficial supplement in fish.Spanish Ministry of Science and Education, Grant/Award Number: AGL2013-48835-C2-R and AGL2016-76069-C2-1-R; Spanish Ministry of Education, Economy and Competitiveness (MINECO); CAPES (Ministry of Education of Brazil, Brazil); PDSE-CAPES (Programa Institucional de Bolsas de Doutorado Sanduíche no Exterior, Grant/Award Number: 5055/14-8); CNPq research fellowshipPeer reviewe

Oxidative stress parameters in juvenile Brazilian flounder Paralichthys orbignyanus (Valenciennes, 1839) (Pleuronectiformes: Paralichthyidae) exposed to cold and heat shocks

The aim of this study was to determine oxidative stress parameters in the liver and gill of Brazilian flounder juveniles (307.0 ± 16.0 g and 30.0 ± 4.0 cm) submitted to different water temperature (17.1, 23.0 and 28.8ºC) for 72 h and maintained at salinity 25‰. After the acclimation of 7 days, in 23ºC, fish were transferred to 200 L tanks containing seawater (salinity 25‰) at 28.8ºC (heat shock), 17.1ºC (cold shock) or 23.0ºC (control), five replicates (five fish tank-1). The sampled collection occurred in 0 (pre-challenge), 3, 24, 48 and 72 h after temperature shock. Flounder exposed to 17.1ºC and 28.8ºC showed significantly higher TBARS levels and GST activity in the liver post-exposition (PE) in relation to the control (23ºC). CAT activity in liver present a significantly increase at 17.1ºC, in first 48 h, and subsequently decrease in 72 h PE in relation to 28.8ºC. The gills of flounder showed significantly higher TBARS levels, GST and CAT activity when submitted at 17.1 and 28.8ºC in relation to 23.0ºC. There were observed changes in lipid peroxidation levels (LPO), CAT and GST activities in the liver and gill of Brazilian flounder in response to reactive oxygen species (ROS) produced by thermal shocks