Effects of environmental anoxia and different periods of reoxygenation on oxidative balance in gills of the estuarine crab Chasmagnathus granulata
ABSTRACT We investigated the effects of anoxia (8 h) and different periods of reoxygenation (20 and 40 min) on the oxidative balance in anterior and posterior gills of the crab Chasmagnathus granulata. Enzyme activity of catalase and GST was increased in the gills of the animals submitted to anoxia, and SOD activity was decreased. These enzymes returned approximately to control levels during the anoxia recovery time. These results demonstrated enzyme activities change with variations in environmental oxygen levels. The posterior gills showed a higher antioxidant enzyme activity than anterior gills. In the gills, there were no changes in the non-enzymatic antioxidant system (TRAP) during anoxia. On the other hand, during anoxia recovery, an increase of TRAP in both gills was observed. Anoxia does not change lipid peroxidation (TBARS) in the gills. During anoxia recuperation, an increase in levels of TBARS was observed. Thus the results demonstrate that C. granulata has a similar strategy of preparation for oxidative stress as observed in other intertidal species, enabling the crabs to survive in an environment with extreme variations in physical and chemical characteristics, such as salt marshes.
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- "The decrease of proteins in March and only in the hepatopancreas could be related to the surplus of energy required for molting during April–June. In crustaceans, protein contents and its seasonal variation have been attributed to its role as an energy source, as well as with the availability and type of food (Oliveira et al., 2005; Vinagre et al., 2007). A decrease of protein content in the muscle of the crayfish Parastocus varicosus during the period of food scarcity may contribute to the maintenance and survival (da Silva-Castiglioni et al., 2007). "
ABSTRACT: Environmental and physiological variations influence the steady-state concentration of free oxygen radicals in cells. Because of the seasonal life cycle of Lithodes santolla in the Beagle Channel, a baseline study of the antioxidant physiological variations along the seasons is necessary for a better understanding of its ecophysiology. The aim of this study was to evaluate the seasonal variations in gills, haemolymph, muscle and hepatopancreas of the: i) enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione transferase; ii) ascorbic acid and total glutathione; iii) lipid peroxidation and protein oxidation; iv) glucose, proteins and pH. Seasonality found in the antioxidant defense system of L. santolla from the Beagle Channel acts in a collaborative way during the most relevant life cycle phases (reproduction and molting), avoiding a long term oxidative stress. The antioxidant system also shows changes in the enzymatic activities likely caused by the environmental factors, such as low temperatures during winter and spring seasons. Copyright © 2014. Published by Elsevier Inc.Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology 11/2014; 181. DOI:10.1016/j.cbpa.2014.11.016 · 2.37 Impact Factor
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- "The HSC70/HSP70 concentrations were greatest in the near-future warming scenario for both developmental stages, with hatchlings showing the largest increase (Fig. 6C). The increased metabolic demands faced by the hatchlings must lead to elevated ROS formation, and HSPs are among the molecules that can eliminate/change the molecular configuration of ROS . Concomitantly, warming also led to an augment of MDA concentrations (see correlative values in Table S4), indicative of the enhancement of ROS action in organism’s lipids (“peroxidation”), a process considered to be one of the most frequent cellular injury mechanisms . "
ABSTRACT: The knowledge about the capacity of organisms' early life stages to adapt to elevated temperatures is very limited but crucial to understand how marine biota will respond to global warming. Here we provide a comprehensive and integrated view of biological responses to future warming during the early ontogeny of a keystone invertebrate, the squid Loligo vulgaris. Recently-spawned egg masses were collected and reared until hatching at present day and projected near future (+2°C) temperatures, to investigate the ability of early stages to undergo thermal acclimation, namely phenotypic altering of morphological, behavioural, biochemical and physiological features. Our findings showed that under the projected near-future warming, the abiotic conditions inside the eggs promoted metabolic suppression, which was followed by premature hatching. Concomitantly, the less developed newborns showed greater incidence of malformations. After hatching, the metabolic burst associated with the transition from an encapsulated embryo to a planktonic stage increased linearly with temperature. However, the greater exposure to environmental stress by the hatchlings seemed to be compensated by physiological mechanisms that reduce the negative effects on fitness. Heat shock proteins (HSP70/HSC70) and antioxidant enzymes activities constituted an integrated stress response to ocean warming in hatchlings (but not in embryos). The stressful abiotic conditions inside eggs are expected to be aggravated under the projected near-future ocean warming, with deleterious effects on embryo survival and growth. Greater feeding challenges and the lower thermal tolerance limits of the hatchlings are strictly connected to high metabolic demands associated with the planktonic life strategy. Yet, we found some evidence that, in the future, the early stages might support higher energy demands by adjusting some cellular functional properties to increase their thermal tolerance windows.PLoS ONE 06/2012; 7(6):e38282. DOI:10.1371/journal.pone.0038282 · 3.23 Impact Factor
Bioenergetics, 03/2012; , ISBN: 978-953-51-0090-4
- "ategy to prepare the organisms for oxidative stress in an effort to protect tissues against oxidative damage during re - oxygenation . An important decrease in SOD activity ( which occurred after aerobic recuperation ) was also detected ; and it could have been caused by the accumulation of hydrogen peroxide production during re - oxygenation ( de Oliveira et al . , 2005 ) . At normoxia , the small levels of ROS produced by the metabolism in normal animal mitochondria come from carrying electrons along the mitochondrial complexes I , II , and III ( Turrens , 2003 ) . However , when oxygen levels are reduced , the presence of the final electron acceptor in the mitochondrial respiratory chain fails , prod"