Alcohol hangover:impairments in behavior and bioenergetics in central nervous system

Alcohol hangover(AH)is defined as the temporary state after alcohol binge-like drinking,starting when EtOH is absent in plasma.Results from our laboratory have shown behavioral impairments and mitochon-drial dysfunction in an experimental model of AH in mice.Our model consisted in a single i.p.injection of EtOH(3.8 g/kg BW)or saline solution in male and female mice,sacrificing the animals 6 hours after injection.Motor and affective behavior together with mitochondrial function and free radical production were evaluated in brain cortex and cerebellum during AH.Results showed that hangover animals exhibited a significant reduction in neuromus-cular coordination,motor strength and locomotion together with a loss of gait stability and walking deficiencies.Moreover,an increment in anxiety-like behavior together with fear-related phenotype and depression signs were observed.In relation to bioenergetics metabolism,AH induced a reduction in oxygen uptake,inhibition of respira-tory complexes,changes in mitochondrial membrane permeability,decrease in transmembrane potential,increase in O2•-and H2O2 production and impairment in nitric oxide metabolism.All together our data suggest that the phys-iopathological state of AH involves behavioral impairments and mitochondrial dysfunction in mouse brain cortex and cerebellum showing the long lasting effects of acute EtOH exposure in CNS.

Oxidative stress in the hydrophilic medium of algae and invertebrates

The harmful effects of the reactive species may be due to the increase in their steady state concentration either by the enhancement of their production rates and/or the decrease of their consumption rate by antioxidant activity.The ascorbyl radical(A^(·))can be considered as a final product of radical oxidative transformations of ascorbate(AH^(-)).The ratio A^(·)content/AH^(-)content(A^(·)/AH^(-))has been widely used as an interesting tool to estimate mild to moderate oxidative transformations,providing a quick and simple method of diagnosis of stress in the hydrophilic cellular medium.The aim of this work was to summarize studies on the cellular oxidative condition in algae and invertebrates by assessing the A^(·)/AH^(-)ratio under environmentally changing conditions.The use of indices of oxidative stress increasingly sensitive and,somewhat more specific,can bring a new light to the still unknown world of oxidative responses in marine organisms.

Oxidative stress in Microcystis aeruginosa as a consequence of global climate change

Cyanobacteria are phototrophic organisms with great ecological and economical importance.Species of the genus Microcystis are known for their potential ability to synthesize toxins,notably microcystins.There is a growing interest in the evaluation of oxidative stress in relation to the impact of global climate change on natural ecosystems in different trophic levels.Several studies have focused on the analysis of organismal responses to mitigate the damage by controlling the generation of reactive oxygen species.Variations in environ-mental factors caused by climate change generate a situation of oxidative damage in Microcystis aeruginosa as a direct or indirect consequence.In this study we evaluate the effects of ultraviolet radiation and temperature on physiological and biochemical responses of a native M.aeruginosa(strain CAAT 2005-3).The results from the exposure to ultraviolet radiation doses and temperature changes suggest a high ability of M.aeruginosa to detect a potential stress situation as a consequence of reactive species production and to rapidly initiate antioxidant defenses.Increased catalase activity is an antioxidant protection mechanism in M.aeruginosa for short and long term exposure to different changes in environmental conditions.However,we found a ultraviolet-B radiation threshold dose above which oxidative stress exceeds the antioxidant protection and damage occurs.In addition our results are in agreement with recent findings suggesting that microcystins may act as protein-modulating metabolites and protection against reactive oxygen species.It is concluded that cyanobacteria have adaptative mechanisms that could lead to the replacement of species highly susceptible to oxidative stress by others with a higher system of antioxidant protection.

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 low lipid 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.