Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish)
Abstract In elasmobranchs, triglycerides are stored in the liver, which appears to be the primary site for lipolysis and oxidation of fatty acids, a major product being ketone bodies. The objective of this study was to obtain comparative information about properties of ketone body and phosphoenolpyr...
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crwiley:10.1002/jez.1402540206 2024-06-02T08:16:04+00:00 Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) Anderson, Paul M. 1990 http://dx.doi.org/10.1002/jez.1402540206 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjez.1402540206 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jez.1402540206 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Experimental Zoology volume 254, issue 2, page 144-154 ISSN 0022-104X 1097-010X journal-article 1990 crwiley https://doi.org/10.1002/jez.1402540206 2024-05-03T11:09:03Z Abstract In elasmobranchs, triglycerides are stored in the liver, which appears to be the primary site for lipolysis and oxidation of fatty acids, a major product being ketone bodies. The objective of this study was to obtain comparative information about properties of ketone body and phosphoenolpyruvate formation by liver of Squalus acanthias (spiny dogfish, a representative elasmobranch) by using an isolated hepatic mitochondrial system we have previously described for studying respiration and glutamine‐dependent citrulline synthesis. Acetate and palmitoyl‐CoA are stoichiometrically converted to ketone bodies at a rapid rate. The capability of mitochondria to convert short‐chain fatty acids to ketone bodies indicates that the previously reported inability of dogfish mitochondria to utilize short‐chain fatty acids to support respiration is not due to absence of nucleoside monophosphate kinase activity. At least two acyl‐CoA synthetase activities are present in mitochondrial extracts, one specific for acetate and another with specificity for longer‐chain fatty acids. Utilization of palmitoyl‐CoA is carnitine‐dependent and is inhibited by low concentrations of malonyl‐CoA. Pyruvate and alanine are also rapidly metabolized to ketone bodies. Phosphoenolpyruvate is formed at a significant rate from a number of substrates, including in particular aspartate and malate in the presence of α‐ketoglutarate. The osmolytes urea and trimethylamine oxide activate and inhibit, respectively, phosphoenolpyruvate formation; in contrast, these osmolytes inhibit and activate, respectively, ketone body and citrulline formation by isolated mitochondria. The results are consistent with the reported unique functions of dogfish liver in lipid metabolism and indicate that the basic enzymatic processes at the level of mitochondria appear to be analogous to those present in mammalian species. Article in Journal/Newspaper spiny dogfish Squalus acanthias Wiley Online Library Journal of Experimental Zoology 254 2 144 154 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract In elasmobranchs, triglycerides are stored in the liver, which appears to be the primary site for lipolysis and oxidation of fatty acids, a major product being ketone bodies. The objective of this study was to obtain comparative information about properties of ketone body and phosphoenolpyruvate formation by liver of Squalus acanthias (spiny dogfish, a representative elasmobranch) by using an isolated hepatic mitochondrial system we have previously described for studying respiration and glutamine‐dependent citrulline synthesis. Acetate and palmitoyl‐CoA are stoichiometrically converted to ketone bodies at a rapid rate. The capability of mitochondria to convert short‐chain fatty acids to ketone bodies indicates that the previously reported inability of dogfish mitochondria to utilize short‐chain fatty acids to support respiration is not due to absence of nucleoside monophosphate kinase activity. At least two acyl‐CoA synthetase activities are present in mitochondrial extracts, one specific for acetate and another with specificity for longer‐chain fatty acids. Utilization of palmitoyl‐CoA is carnitine‐dependent and is inhibited by low concentrations of malonyl‐CoA. Pyruvate and alanine are also rapidly metabolized to ketone bodies. Phosphoenolpyruvate is formed at a significant rate from a number of substrates, including in particular aspartate and malate in the presence of α‐ketoglutarate. The osmolytes urea and trimethylamine oxide activate and inhibit, respectively, phosphoenolpyruvate formation; in contrast, these osmolytes inhibit and activate, respectively, ketone body and citrulline formation by isolated mitochondria. The results are consistent with the reported unique functions of dogfish liver in lipid metabolism and indicate that the basic enzymatic processes at the level of mitochondria appear to be analogous to those present in mammalian species. |
format |
Article in Journal/Newspaper |
author |
Anderson, Paul M. |
spellingShingle |
Anderson, Paul M. Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
author_facet |
Anderson, Paul M. |
author_sort |
Anderson, Paul M. |
title |
Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
title_short |
Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
title_full |
Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
title_fullStr |
Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
title_full_unstemmed |
Ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from Squalus acanthias (spiny dogfish) |
title_sort |
ketone body and phosphoenolpyruvate formation by isolated hepatic mitochondria from squalus acanthias (spiny dogfish) |
publisher |
Wiley |
publishDate |
1990 |
url |
http://dx.doi.org/10.1002/jez.1402540206 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjez.1402540206 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jez.1402540206 |
genre |
spiny dogfish Squalus acanthias |
genre_facet |
spiny dogfish Squalus acanthias |
op_source |
Journal of Experimental Zoology volume 254, issue 2, page 144-154 ISSN 0022-104X 1097-010X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/jez.1402540206 |
container_title |
Journal of Experimental Zoology |
container_volume |
254 |
container_issue |
2 |
container_start_page |
144 |
op_container_end_page |
154 |
_version_ |
1800740406340616192 |