Mutagenicity of the agriculture pesticide chlorothalonil assessed by somatic mutation and recombination test in Drosophila melanogaster.

Chlorothalonil (CTL) is a pesticide widely used in Brazil, yet its mutagenic potential is not fully determined. Thus, we assessed the mutagenicity of CTL and its bioactivation metabolites using the somatic mutation and recombination test (SMART) in Drosophila melanogaster, by exposing individuals, with basal and high bioactivation capacities (standard and high bioactivation cross offspring, respectively), from third instar larval to early adult fly stages, to CTL-contaminated substrate (0.25, 1, 10 or 20 μM).

Therapeutic Hypothermia Is Limited in Preventing Developmental Impairments after Neonatal Hypoxia-Ischemia.

The only current treatment for neonatal hypoxia-ischemia (HI) is therapeutic hypothermia (TH), which still shows some limitations. Specific effects of TH in the several processes involved in brain injury progression remain unclear. In this study, the effects of TH treatment on developmental parameters, behavioral outcomes, and peripheral leukocytes were evaluated in neonatal male and female rats.

Effects of tributyltin (TBT) on the intermediate metabolism of the crab Callinectes sapidus.

This study investigated if the exposure to tributyltin (TBT), a chemical used worldwide in boat antifouling paints, could result in metabolic disturbances in the blue crab Callinectes sapidus. After the exposure to TBT 100 or 1000 ng.L for 48 and 96 h, hemolymph and tissues were collected to determine the concentration of metabolites and lipid peroxidation.

Seasonal variations in the intermediate metabolism in South American tree-frog Boana pulchella.

Seasonal metabolic changes can be observed in many anurans' species. In subtropical environments with environmental temperatures variations, the temperature is a factor that can influence the extent and intensity of activity in many anuran species. Nonetheless, some species of subtropical frogs may remain active throughout the year.

Lactate Administration Reduces Brain Injury and Ameliorates Behavioral Outcomes Following Neonatal Hypoxia-Ischemia.

Neonatal hypoxic-ischemic encephalopathy is a major cause of mortality and disability in newborns and the only standard approach for treating this condition is therapeutic hypothermia, which shows some limitations. Thus, putative neuroprotective agents have been tested in animal models. The present study evaluated the administration of lactate, a potential energy substrate of the central nervous system (CNS) in an animal model of hypoxia-ischemia (HI), that mimics in neonatal rats the brain damage observed in human newborns.

Characterization of different DNA repair pathways in hepatic cells of Zebrafish (Danio rerio).

The concern about DNA damage has directed efforts toward evaluating the genotoxic potential of physical and chemical agents. Since the extent of DNA damage is also related to the capacity of the organism in repairing the DNA, the advance of toxicological studies on this area depends on the characterization of the DNA repair mechanisms in the available models. The cellular zebrafish models, for example, replace mammalian cells to answer ecologically relevant questions on aquatic toxicology.

Transcriptome Analysis Identifies Key Metabolic Changes in the Hooded Seal (Cystophora cristata) Brain in Response to Hypoxia and Reoxygenation.

The brain of diving mammals tolerates low oxygen conditions better than the brain of most terrestrial mammals. Previously, it has been demonstrated that the neurons in brain slices of the hooded seal (Cystophora cristata) withstand hypoxia longer than those of mouse, and also tolerate reduced glucose supply and high lactate concentrations. This tolerance appears to be accompanied by a shift in the oxidative energy metabolism to the astrocytes in the seal while in terrestrial mammals the aerobic energy production mainly takes place in neurons.

When the brain goes diving: transcriptome analysis reveals a reduced aerobic energy metabolism and increased stress proteins in the seal brain.

Background: During long dives, the brain of whales and seals experiences a reduced supply of oxygen (hypoxia). The brain neurons of the hooded seal (Cystophora cristata) are more tolerant towards low-oxygen conditions than those of mice, and also better survive other hypoxia-related stress conditions like a reduction in glucose supply and high concentrations of lactate. Little is known about the molecular mechanisms that support the hypoxia tolerance of the diving brain.

An atypical distribution of lactate dehydrogenase isoenzymes in the hooded seal (Cystophora cristata) brain may reflect a biochemical adaptation to diving.

The brains of some diving mammals can withstand periods of severe hypoxia without signs of deleterious effects. This may in part be due to an enhanced cerebral capacity for anaerobic energy production. Here, we have tested this hypothesis by comparing various parameters of the lactate dehydrogenase (LDH) in the brain of the hooded seal (Cystophora cristata) with those in the brains of the ferret (Mustela putorius furo) and mouse (Mus musculus).

Oxidative stress and DNA damage responses to phenanthrene exposure in the estuarine guppy Poecilia vivipara.

Despite ubiquitous phenanthrene contamination in aquatic coastal areas, little is known regarding its potential effects on estuarine fishes. The present work evaluated the response of a large suite of oxidative stress- and DNA damage-related biomarkers to phenanthrene exposure (10, 20 and 200 μg L(-1), 96 h) using DMSO as the solvent in estuarine guppy Poecilia vivipara (salinity 24 psu). Phenanthrene affected oxidative stress-related parameters, and decreased antioxidant defenses and reactive oxygen species in the gills and muscle overall.

Biomarkers of waterborne copper exposure in the guppy Poecilia vivipara acclimated to salt water.

The responses of a large suite of biochemical and genetic parameters were evaluated in tissues (liver, gills, muscle and erythrocytes) of the estuarine guppy Poecilia vivipara exposed to waterborne copper in salt water (salinity 24 ppt). Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase, and glutathione S-transferase), metallothionein-like protein concentration, reactive oxygen species (ROS) content, antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO) were evaluated in liver, gills, and muscle. Comet assay score and nuclear abnormalities and micronucleated cell frequency were analyzed in peripheral erythrocytes.

Evaluation of redox and bioenergetics states in the liver of vitamin A-treated rats.

Vitamin A is normally stored in the mammalian liver and is physiologically released depending on the need of the organism for the vitamin. However, there is a compelling evidence showing that even the liver is affected by conditions of high vitamin A intake. Based on these previously reported findings showing negative effects of vitamin A on mammalian tissues, we have investigated the effects of a supplementation with vitamin A at clinical doses (1000-9000 IU/kg day(-1)) on some rat liver parameters.

Evaluation of the effects of vitamin A supplementation on adult rat substantia nigra and striatum redox and bioenergetic states: mitochondrial impairment, increased 3-nitrotyrosine and alpha-synuclein, but decreased D2 receptor contents.

Vitamin A at moderate to high doses is applied in the treatment of some life threatening pathological conditions, for instance cancers. Additionally, vitamin A at low concentrations is a known antioxidant molecule. However, by increasing vitamin A (or its derivatives) concentrations, there is an increase in the levels of oxidative stress markers in several experimental models.

Decreased anxiety-like behavior and locomotor/exploratory activity, and modulation in hypothalamus, hippocampus, and frontal cortex redox profile in sexually receptive female rats after short-term exposure to male chemical cues.

Chemical cues are widely used for intraspecific social communication in a vast majority of living organisms ranging from bacteria to mammals. As an example, mammals release olfactory cues with urine that promote neuroendocrine modulations with changes in behavior and physiology in the receiver. In this work, four-month-old Wistar (regular 4-day cyclic) virgin female rats were utilized in the proestrus-to-estrus phase of the reproductive cycle for experimental exposure.