The loss of hemoglobin and myoglobin does not minimize oxidative stress in Antarctic icefishes

摘要: ABSTRACT The unusual pattern of expression hemoglobin (Hb) and myoglobin (Mb) among Antarctic notothenioid fishes provides an exceptional model system for assessing the impact these proteins on oxidative stress. We tested hypothesis that lack oxygen-binding may reduce Levels activity pro-oxidants small-molecule enzymatic antioxidants, levels oxidized lipids in liver, skeletal muscle heart ventricle were quantified five species differing Hb Mb. ubiquitinated rates protein degradation by 20S proteasome also quantified. Although lipids, proteins, antioxidants higher red-blooded than Hb-less icefishes some tissues, this did not persist across all tissues. Expression Mb was associated with damage ventricle, whereas citrate synthase contents heme positively correlated most Despite tissue differences carbonyls species, markedly different, suggesting either alternative pathways eliminating or redox tone varies species. Together, our data indicate loss does correspond a clear reduced defense damage.