Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals
Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin–angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH...
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ftcalifstateuniv:oai:scholarworks:sn009z39n 2024-09-30T14:34:23+00:00 Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals José Pablo Vázquez-Medina Tania Zenteno-Savín Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz 2011-04 http://hdl.handle.net/10211.3/118195 English eng Journal of Experimental Biology J.P.V.-M. is supported by fellowships from UC MEXUS-CONACYT and Mexico’s Ministry of Education (SEP). Research funded by NHLBI R01-HL091767 (R.M.O., D.E.C.) and UC MEXUS-CONACYT (R.M.O., T.Z.-S.). http://hdl.handle.net/10211.3/118195 prolonged fasting glutathione northern elephant seal pup Article 2011 ftcalifstateuniv 2024-09-10T17:06:15Z Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin–angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-s transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], -glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in -glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40–50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma -glutamyl glutamine, -glutamyl isoleucine and -glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals. Published by and copyright of The Company of Biologists. The definitive version of this article is available at: http://jeb.biologists.org/content/214/8/1294.full.pdf+html Vázquez-Medina, José ... Article in Journal/Newspaper Elephant Seal Elephant Seals Scholarworks from California State University Medina ENVELOPE(-66.233,-66.233,-68.453,-68.453) |
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Scholarworks from California State University |
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language |
English |
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prolonged fasting glutathione northern elephant seal pup |
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prolonged fasting glutathione northern elephant seal pup José Pablo Vázquez-Medina Tania Zenteno-Savín Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
topic_facet |
prolonged fasting glutathione northern elephant seal pup |
description |
Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin–angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-s transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], -glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in -glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40–50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma -glutamyl glutamine, -glutamyl isoleucine and -glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals. Published by and copyright of The Company of Biologists. The definitive version of this article is available at: http://jeb.biologists.org/content/214/8/1294.full.pdf+html Vázquez-Medina, José ... |
format |
Article in Journal/Newspaper |
author |
José Pablo Vázquez-Medina Tania Zenteno-Savín Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz |
author_facet |
José Pablo Vázquez-Medina Tania Zenteno-Savín Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz |
author_sort |
José Pablo Vázquez-Medina |
title |
Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
title_short |
Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
title_full |
Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
title_fullStr |
Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
title_full_unstemmed |
Prolonged Fasting Increases Glutathione Biosynthesis in Postweaned Northern Elephant Seals |
title_sort |
prolonged fasting increases glutathione biosynthesis in postweaned northern elephant seals |
publisher |
Journal of Experimental Biology |
publishDate |
2011 |
url |
http://hdl.handle.net/10211.3/118195 |
long_lat |
ENVELOPE(-66.233,-66.233,-68.453,-68.453) |
geographic |
Medina |
geographic_facet |
Medina |
genre |
Elephant Seal Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals |
op_relation |
http://hdl.handle.net/10211.3/118195 |
_version_ |
1811638017736048640 |