Proline catabolism in liver
Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biochemistry Includes bibliographical references (leaves 114-133) The goal of this work was to localize one of the enzymes involved in proline oxidation, Δ1 -pyrroline-5-carboxylate dehydrogenase (P5CDh) and to gain an understanding of the f...
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ftmemorialunivdc:oai:collections.mun.ca:theses4/72485 2023-05-15T17:23:33+02:00 Proline catabolism in liver Haslett, Michael Roland, 1968- Memorial University of Newfoundland. Dept. of Biochemistry 2009 ix, 133 leaves : ill. Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses4/id/72485 Eng eng Electronic Theses and Dissertations (14.41 MB) -- http://collections.mun.ca/PDFs/theses/Haslett_MichaelRonald.pdf a2981456 http://collections.mun.ca/cdm/ref/collection/theses4/id/72485 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Liver--Metabolism Proline--Metabolism Rats--Anatomy Text Electronic thesis or dissertation 2009 ftmemorialunivdc 2015-08-06T19:22:11Z Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biochemistry Includes bibliographical references (leaves 114-133) The goal of this work was to localize one of the enzymes involved in proline oxidation, Δ1 -pyrroline-5-carboxylate dehydrogenase (P5CDh) and to gain an understanding of the factors affecting proline catabolism in rat liver. In this regard we performed a systematic subcellular localization for P5CDh and studied proline catabolism in response to dietary protein and exogenous glucagon. Our results indicate that P5CDh is located solely in mitochondria in rat liver. With respect to factors affecting proline catabolism we observed that rats fed a diet containing excess protein (45% casein) display a 1.5 fold increase in activity of P5CDh and proline oxidase (PO), and a 40% increase in flux through the pathway resulting in complete oxidation of proline in isolated mitochondria. We also observed that rats administered exogenous glucagon exhibit a 2 fold increase in PO activity and a 1.5 fold increase in P5CDh activity, and a 2 fold increase in flux through the pathway resulting in complete oxidation of proline in isolated mitochondria. 14 CO2 production from 14 C-proline in the isolated nonrecirculating perfused rat liver was also elevated 2 fold in the glucagon treated rat. We also studied the transport of proline into isolated hepatocytes and observed a 1.5 fold increase in the transport of proline in rats given exogenous glucagon. -- Conclusions. Subcellular localization: (a) The spectrophotometric assay is valid and provides a quick, easy method for assays of P5CDh (b) P5CDh is located strictly in the mitochondrial matrix. High protein diet increases: (a) flux through the proline catabolic pathway in mitochondria resulting in the production of CO 2 (b) activity of PO, P5CDh, and ornithine aminotransferase (OAT) in rat liver mitochondria Glucagon increases: (a) proline transfer from plasma to hepatocytes (b) oxidation of proline by perfused liver (c) flux through the proline catabolic pathway resulting in the production of CO 2 (d) activity of PO, P5CDH and glutamate dehydrogenase (GDH) in rat liver mitochondria Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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English |
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Liver--Metabolism Proline--Metabolism Rats--Anatomy |
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Liver--Metabolism Proline--Metabolism Rats--Anatomy Haslett, Michael Roland, 1968- Proline catabolism in liver |
topic_facet |
Liver--Metabolism Proline--Metabolism Rats--Anatomy |
description |
Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biochemistry Includes bibliographical references (leaves 114-133) The goal of this work was to localize one of the enzymes involved in proline oxidation, Δ1 -pyrroline-5-carboxylate dehydrogenase (P5CDh) and to gain an understanding of the factors affecting proline catabolism in rat liver. In this regard we performed a systematic subcellular localization for P5CDh and studied proline catabolism in response to dietary protein and exogenous glucagon. Our results indicate that P5CDh is located solely in mitochondria in rat liver. With respect to factors affecting proline catabolism we observed that rats fed a diet containing excess protein (45% casein) display a 1.5 fold increase in activity of P5CDh and proline oxidase (PO), and a 40% increase in flux through the pathway resulting in complete oxidation of proline in isolated mitochondria. We also observed that rats administered exogenous glucagon exhibit a 2 fold increase in PO activity and a 1.5 fold increase in P5CDh activity, and a 2 fold increase in flux through the pathway resulting in complete oxidation of proline in isolated mitochondria. 14 CO2 production from 14 C-proline in the isolated nonrecirculating perfused rat liver was also elevated 2 fold in the glucagon treated rat. We also studied the transport of proline into isolated hepatocytes and observed a 1.5 fold increase in the transport of proline in rats given exogenous glucagon. -- Conclusions. Subcellular localization: (a) The spectrophotometric assay is valid and provides a quick, easy method for assays of P5CDh (b) P5CDh is located strictly in the mitochondrial matrix. High protein diet increases: (a) flux through the proline catabolic pathway in mitochondria resulting in the production of CO 2 (b) activity of PO, P5CDh, and ornithine aminotransferase (OAT) in rat liver mitochondria Glucagon increases: (a) proline transfer from plasma to hepatocytes (b) oxidation of proline by perfused liver (c) flux through the proline catabolic pathway resulting in the production of CO 2 (d) activity of PO, P5CDH and glutamate dehydrogenase (GDH) in rat liver mitochondria |
author2 |
Memorial University of Newfoundland. Dept. of Biochemistry |
format |
Thesis |
author |
Haslett, Michael Roland, 1968- |
author_facet |
Haslett, Michael Roland, 1968- |
author_sort |
Haslett, Michael Roland, 1968- |
title |
Proline catabolism in liver |
title_short |
Proline catabolism in liver |
title_full |
Proline catabolism in liver |
title_fullStr |
Proline catabolism in liver |
title_full_unstemmed |
Proline catabolism in liver |
title_sort |
proline catabolism in liver |
publishDate |
2009 |
url |
http://collections.mun.ca/cdm/ref/collection/theses4/id/72485 |
genre |
Newfoundland studies University of Newfoundland |
genre_facet |
Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (14.41 MB) -- http://collections.mun.ca/PDFs/theses/Haslett_MichaelRonald.pdf a2981456 http://collections.mun.ca/cdm/ref/collection/theses4/id/72485 |
op_rights |
The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. |
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1766113265201446912 |