Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia
The free radical nitric oxide (NO) is a powerful metabolic regulator in vertebrates and invertebrates. At cellular concentrations in the nanomolar range, and simultaneously reduced internal oxygen partial pressures (pO(2)), NO completely inhibits cytochrome-c-oxidase (CytOx) activity and hence mitoc...
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ftpubmed:oai:pubmedcentral.nih.gov:7205294 2023-05-15T15:22:31+02:00 Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia Strahl, Julia Abele, Doris 2020-05-07 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205294/ http://www.ncbi.nlm.nih.gov/pubmed/32379772 https://doi.org/10.1371/journal.pone.0232360 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205294/ http://www.ncbi.nlm.nih.gov/pubmed/32379772 http://dx.doi.org/10.1371/journal.pone.0232360 © 2020 Strahl, Abele http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY PLoS One Research Article Text 2020 ftpubmed https://doi.org/10.1371/journal.pone.0232360 2020-05-17T00:24:24Z The free radical nitric oxide (NO) is a powerful metabolic regulator in vertebrates and invertebrates. At cellular concentrations in the nanomolar range, and simultaneously reduced internal oxygen partial pressures (pO(2)), NO completely inhibits cytochrome-c-oxidase (CytOx) activity and hence mitochondrial- and whole-tissue respiration. The infaunal clam Arctica islandica regulates pO(2) of hemolymph and mantle cavity water to mean values of <5 kPa, even in a completely oxygen-saturated environment of 21 kPa. These low internal pO(2) values support a longer NO lifespan and NO accumulation in the body fluids and can thus trigger a depression of metabolic rate in the clams. Measurable amounts of NO formation were detected in hemocyte cells (~110 pmol NO 100(−1) hemocytes h(-1) at 6 kPa), which was not prevented in the presence of the NO synthase inhibitor L-NAME, and in the gill filaments of A. islandica. Adding a NO donor to intact gills and tissue homogenate significantly inhibited gill respiration and CytOx activity below 10 kPa. Meanwhile, the addition of the NO-oxidation product nitrite did not affect metabolic rates. The high nitrite levels found in the hemolymph of experimental mussels under anoxia do not indicate cellular NO production, but could be an indication of nitrate reduction by facultative anaerobic bacteria associated with tissue and/or hemolymph biofilms. Our results suggest that NO plays an important role in the initiation of metabolic depression during self-induced burrowing and shell closure of A. islandica. Furthermore, NO appears to reduce mitochondrial oxygen radical formation during surfacing and cellular reoxygenation after prolonged periods of hypoxia and anoxia. Text Arctica islandica PubMed Central (PMC) PLOS ONE 15 5 e0232360 |
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Research Article Strahl, Julia Abele, Doris Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
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Research Article |
description |
The free radical nitric oxide (NO) is a powerful metabolic regulator in vertebrates and invertebrates. At cellular concentrations in the nanomolar range, and simultaneously reduced internal oxygen partial pressures (pO(2)), NO completely inhibits cytochrome-c-oxidase (CytOx) activity and hence mitochondrial- and whole-tissue respiration. The infaunal clam Arctica islandica regulates pO(2) of hemolymph and mantle cavity water to mean values of <5 kPa, even in a completely oxygen-saturated environment of 21 kPa. These low internal pO(2) values support a longer NO lifespan and NO accumulation in the body fluids and can thus trigger a depression of metabolic rate in the clams. Measurable amounts of NO formation were detected in hemocyte cells (~110 pmol NO 100(−1) hemocytes h(-1) at 6 kPa), which was not prevented in the presence of the NO synthase inhibitor L-NAME, and in the gill filaments of A. islandica. Adding a NO donor to intact gills and tissue homogenate significantly inhibited gill respiration and CytOx activity below 10 kPa. Meanwhile, the addition of the NO-oxidation product nitrite did not affect metabolic rates. The high nitrite levels found in the hemolymph of experimental mussels under anoxia do not indicate cellular NO production, but could be an indication of nitrate reduction by facultative anaerobic bacteria associated with tissue and/or hemolymph biofilms. Our results suggest that NO plays an important role in the initiation of metabolic depression during self-induced burrowing and shell closure of A. islandica. Furthermore, NO appears to reduce mitochondrial oxygen radical formation during surfacing and cellular reoxygenation after prolonged periods of hypoxia and anoxia. |
format |
Text |
author |
Strahl, Julia Abele, Doris |
author_facet |
Strahl, Julia Abele, Doris |
author_sort |
Strahl, Julia |
title |
Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
title_short |
Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
title_full |
Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
title_fullStr |
Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
title_full_unstemmed |
Nitric oxide mediates metabolic functions in the bivalve Arctica islandica under hypoxia |
title_sort |
nitric oxide mediates metabolic functions in the bivalve arctica islandica under hypoxia |
publisher |
Public Library of Science |
publishDate |
2020 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205294/ http://www.ncbi.nlm.nih.gov/pubmed/32379772 https://doi.org/10.1371/journal.pone.0232360 |
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Arctica islandica |
genre_facet |
Arctica islandica |
op_source |
PLoS One |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205294/ http://www.ncbi.nlm.nih.gov/pubmed/32379772 http://dx.doi.org/10.1371/journal.pone.0232360 |
op_rights |
© 2020 Strahl, Abele http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
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CC-BY |
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https://doi.org/10.1371/journal.pone.0232360 |
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PLOS ONE |
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15 |
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