Acute Fe-dextran treatment and redox balance in rat whole brain and cortex

An acute Fe-dextran treatment produced oxidative stress in rat brain that lead to the translocation of Nrf2 to the cell nucleus, producing the activation of genes involved in the glutathione metabolism in the cellular environment. Previous reports have shown that the acute Fe overload produced by a single injection of Fe-dextran resulted in a significant decrease in total thiol and glutathione content in rat cortex area after 6 and 8 h post injection (pi). In the whole brain, enzymatic activities of glutathione-S-transferase (GST) and glutathione peroxidase (GPx), and total thiol content were increased as compared to control tissues at 6 or 8 h pi, respectively. The aim of this study was to determine the effect of acute Fe overload on glutathione-dependent enzymatic metabolism in cortex rat brain. A single dose of 500 mg Fe-dextran/kg body weight was administrated intraperitoneally to male Sprague Dawley rats. Total brain samples or cortex area were obtained from control and treated animals after 6 or 8 h pi. Glutathione reductase (GR) was determined spectrophotometrically. Reduced glutathione (GSH), oxidized glutathione (GSSG) and malondialdehyde (MDA) content were determined by reverse phase HPLC. MDA content showed a significant increased (p<0.05) at 8 h pi in whole brain. A significant decrease in cortical GSH (p<0.05), and a significant increase in cortical GSSG (p<0.05) was observed at 8 h pi. A slight but non-significant reduction in the activity of the enzyme GR was seen at 6 and 8 h pi in brain cortex. Taking as a whole, these results suggested that the increase in the GSSG/GSH ratio could be associated to the increase in the activities of GST and GPx without any change in GR activity in brain cortex. Moreover, it seems that the alteration in the redox status caused by the Fe treatment in the cortex could contribute to the lipid peroxidation changes detected in the whole brain.Fil: Piloni, Natacha Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Robello, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaLXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica; LI Reunión Anual de la Asociación Argentina de Farmacología Experimental; XXI Reunión Anual de la Sociedad Argentina de Biología; XXXI Reunión Anual de la Sociedad Argentina de Protozoología; IX Reunión Anual de la Asociación Argentina de Nanomedicinas y VI Reunión Científica Regional de la Asociación Argentina de Ciencia y Tecnología de Animales de LaboratorioMar del PlataArgentinaSociedad Argentina de Investigación ClínicaAsociación Argentina de Farmacología ExperimentalSociedad Argentina de BiologíaSociedad Argentina de ProtozoologíaAsociación Argentina de NanomedicinasAsociación Argentina de Ciencia y Tecnología de Animales de Laboratori

Análisis de una evaluación diagnóstica como mejora de la práctica educativa

La Facultad de Farmacia y Bioquímica de la Universidad de Buenos Aires implementa evaluaciones diagnósticas para determinar la evolución académica de diferentes cohortes de alumnos, analizar los planes de estudio y promover la articulación vertical y transversal entre asignaturas. En parte, debido a estas acciones, en2016 se realizó una modificación en el plan de estudio de las carreras de Farmacia y de Bioquímica de esta Facultad. La asignatura Fisicoquímica implementa la misma evaluación diagnóstica desde el 2015. Con el objetivo de determinar qué información nos ha dado esta evaluación entre los años 2015 y 2019, se analizaron los datos brindados por la misma (como porcentaje de respuestas correctas a las preguntas realizadas). El análisis realizado proporcionó elementos para decidir diferentes tipos de acciones sobre las preguntas. Algunas preguntas no deberían ser modificadas ya que brindan información sobre contenidos aprendidos erróneamente. Otras, que no informan datos novedosos para mejorar la práctica docente, podrían ser reemplazadas para incluir aquellas que indaguen sobre contenidos y habilidades necesarios para el buen desempeño en la asignatura. Finalmente, el análisis realizado indicó que el cambio de plan de estudio no produjo modificaciones significativas sobre los datos obtenidos.The School of Pharmacy and Biochemistry of the University of Buenos Aires regularly implements diagnostic evaluations to determine the academic evolution of different cohorts of students, analyze the study plans, and promote vertical and transversal articulation between subjects. In part, due to these actions, in 2016 a modification was made to the study plan of careers of this School. Physical chemistry implements the same diagnostic evaluation since 2015. In order to determine what information this evaluation has given us between the years 2015 and 2019, the obtained data was analyzed (as a percentage of correct answers to the questions). The analysis carried out provided elements to decide different types of actions on the questions. Some of them should not be modified as they provide information on wrongly learned content. Others, which do not report novel data to improve teaching practice, could be replaced to include those that inquire about content and skills necessary for good performance in Physical chemistry. Finally, the analysis carried out indicated that the change in the study plan did not produce significant modifications on the data obtained.Fil: Galleano, Mónica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Robello, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Update on Fe-dependent oxidative metabolism in vivo: an integrative view

Fe is essential for human life because it constitutes the required cofactor for proteins of diverse biological functions. However, the development of oxidative stress by exposure to excessive Fe, share signaling pathways with other treatments including activation of redox-sensitive factors. This study was focused on the comparison on the effects of Fe in the brain and other organs in vivo. The oxidative effects triggered by Fe overload strongly depend not only on the administration protocol, but also on the Fe-compound used, and the studied organ. In both the liver and the brain, Fe content drastically increased after Fe-dextran administration. However, the comparatively lowlipid peroxidation in the brain as compared to the liver, suggested that Fe-dependent oxidative stress might involve mechanisms of different nature. In the brain, acute and subchronic administration of Fe-dextran triggered signaling processes that lead to the prevention of injury by the participation of catalase activity as an antioxidant protection.This brief summary opens a huge range of possible points of risk, as well as opportunities, to encounter situations in which the appropriate election of the Fe management protocol could be able of allow oxidative stress to exert beneficial effects.Fil: Piloni, Natacha Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Robello, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Bonetto, Julián Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Analysis and optimization of the virtual teaching practice of Applied Physicochemistry

Se analiza la estrategia empleada para el dictado virtual de la asignatura Fisicoquímica Aplicada de la Carrera de Especialización en Esterilización para Farmacéuticos. Se describe el programa de actividades desarrollado puntualizando las Fortalezas/Debilidades y Oportunidades/Amenazas del empleo del Aula Virtual, comparando las observaciones de docentes y alumnos en varias cohortes. Se proponen acciones a implementarse con el objetivo de enriquecer el dictado de la asignatura.Universidad de Buenos AiresInstituto de Fisiología Vegeta

Labile iron pool and ferritin content in developing rat brain γ-irradiated in utero

This study was aimed to assess the content of total Fe, Ferritin (Ft) and labile Fe pool (LIP) in developing rat brain exposed in utero to 1 Gy of gamma irradiation. A significant increase (2.3-fold) in the total Fe content of the fetal rat brain irradiated in utero was observed from 1 to 4 h post-irradiation, as compared to the content in non-irradiated brain. Ft was analyzed by immunoblotting. The Ft protein was composed by 20 kDa subunits. According to the analysis of the band density in the Western blot, the Ft content decreased by 77 ± 15% 2 h after gamma-irradiation, as compared to the values in non-irradiated samples. The effect of gamma-irradiation on the LIP was studied by both electron paramagnetic resonance (EPR) and by a fluorescence technique employing calcein (CA). A reduction on the LIP was detected at 2 h post-irradiation, independently of the methodology employed for the assay. Since NO content increased in the same time frame of LIP decreasing, a protective role for NO is suggested in fetal rat brain exposed to gamma-irradiation. The data presented in this work are the first experimental evidence suggesting that, as part of the network of the cellular response to limit irradiation-dependent injury, a complex interaction between Fe and NO could be triggered.Fil: Robello, Elizabeth. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Galatro, Andrea Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Oxidative/nitrosative stress evaluation in Fragilaria sp. cultures (Antarctic Diatom) exposed to moderate iron supplementation

The hypothesis tested here was that Fe supplementation at the early stage of development in the Antarctic microalgae Fragilaria sp. lead to changes in the oxidative redox balance at the hydrophilic and lipophilic cellular environment to allow for adequate development and for improving growth. Fe supplementation effect on the Antarctic diatoms was evaluated by the ascorbyl (A?)/ascorbate (AH-) and lipid radical (LR?)/alpha tocopherol (α-T) content ratios, the activity of antioxidant enzymes and the nitrosative metabolism during the microalgae growth stages. In the latent (LAG) phase in the presence of 50 μM Fe, the redox balance in the hydrophilic and in the lipophilic medium showed a significant reduction, as compared to values obtained in control cultures. The cells in LAG phase added with Fe showed a significant reduction in the superoxide dismutase (SOD) activity (36%) and the catalase (CAT) content (72%), and produced a significant reduction in nitric oxide (NO) generation rate, as compared to control cells. Thus, the increase in Fe content, as those seen in the natural habitat, would not be harmful for these diatoms since the microalgae control mechanisms in the early stages avoided drastic increase in the labile Fe pool (LIP).Fil: Robello, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Galatro, Andrea Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Cellular Oxidative/Antioxidant Balance in γ-Irradiated Brain: An Update

Both epidemiological and experimental data indicate that ionizing radiation (IR) may disrupt developmental processes leading to deleterious effects on brain functions. A central role of reactive oxygen (ROS) and nitrogen species (RNS), as important mediators in neurotoxicity and neuroprotection, has been demonstrated. Primary ionization events triggered by IR are amplified and propagated by mechanisms involving ROS and RNS, which activate several signaling pathways leading to final radiation effects. The immature and adult brain display clear differences in the way they respond to insults. Moreover, a great deal of attention is being focus on the limited antioxidant capacity and the particular lipid composition of cell membranes of the developing brain that render it more vulnerable to oxidative stress. The goal of this review is to summarize the current knowledge on the role of alterations in the balance between oxidative/nitrosative stress and antioxidant capacity in the pathways involved in cellular radiation response, with particular focus on the possible therapies proposed to limit radiation-induced effects in the brain.Fil: Robello, Elizabeth. 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: Bonetto, Julián Gerardo. 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: Puntarulo, Susana Ángela. 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; Argentin

Nitric oxide and membrane lipid peroxidation in photosynthetic and non-photosynthetic organisms under several stress conditions

Oxidative damage to lipids was characterized in terms of the nature of the oxidant, the type of lipid, and the severity of the oxidation (Simontacchi et al., 2011). Even though malondialdehyde detection with the thiobarbituric acid reactive substances test (TBARS) is the most currently used assay for the determination of lipid oxidation, it is unspecific since the reaction can be reproduced by other biological compounds (Simontacchi et al., 2011). On the other hand, electron paramagnetic resonance (EPR) spectroscopy showed the capacity of detecting the presence of the lipid radicals (LR•) formed during peroxidation, by yielding unique and stable products with spin traps (Malanga and Puntarulo, 2012)...Fil: Galatro, Andrea Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: González, Paula Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Malanga, Gabriela Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Robello, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Piloni, Natacha Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Nitric oxide and membrane lipid peroxidation in photosynthetic and non-photosynthetic organisms after oxidative stress exposure

Oxidative damage to lipids was characterized in terms of the nature of the oxidant, the type of lipid, and the severity of the oxidation (Simontacchi et al., 2011). Even though malondialdehyde detection with the thiobarbituric acid reactive substances test (TBARS) is the most currently used assay for the determination of lipid oxidation, it is unspecific since the reaction can be reproduced by other biological compounds (Simontacchi et al., 2011). On the other hand, electron paramagnetic resonance (EPR) spectroscopy showed the capacity of detecting the presence of the lipid radicals (LR•) formed during peroxidation, by yielding unique and stable products with spin traps (Malanga and Puntarulo, 2012). Nitric oxide (NO) is recognized both, as a signaling molecule that regulates many enzyme activities, but as a toxic agent as well. It has been found that NO is able to protect animal and plant cell types from oxidative damage resulting from superoxide (O− 2 ), hydrogen peroxide (H2O2) and alkyl peroxides by acting as a terminator of free radical chain reactions (Wink et al., 1995, 1996; Yalowich et al., 1999; Beligni and Lamattina, 2002; Sharpe et al., 2003). Reactive oxygen species (ROS) and reactive nitrogen species (RNS) interact through the reaction of O− 2 with NO, to generate peroxynitrite (ONOO−) at a rate close to diffusion. ONOO− acts as both, a nitrating agent and a powerful oxidant capable of modifying proteins (formation of nitrotyrosine), lipids (lipid oxidation, lipid nitration), and nucleic acids (DNA oxidation and DNA nitration) (Gisone et al., 2004). The purpose of this commentary is to point out that NO complex interactions with other cellular components lead to a wide range of effects depending on the biological system under study and the oxidative stress condition.Fil: Galatro, Andrea Verónica. 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: González, Paula Mariela. 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: Malanga, Gabriela Fabiana. 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: Robello, Elizabeth. 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: Piloni, Natacha Estefanía. 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: Puntarulo, Susana Ángela. 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; Argentin