Persistent Link:
http://hdl.handle.net/10150/184847
Title:
LIPID ABSORPTION AND TRANSPORT IN THE SUCKLING RAT.
Author:
FERNANDO, GERMAIN JITHENDRA.
Issue Date:
1982
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The suckling rat obtains about 70% of its energy from the catabolism of lipid, compared to only about 25% in the adult rat. In addition, lipids are in great demand for membrane synthesis in the rapidly growing tissues. Thus the suckling rat represents an important system in which to study lipid metabolism. In this dissertation research the following experiments were performed on rats during the suckling period: (1) Determination of the concentration and fatty acid composition of triacylglycerols, cholesteryl esters, phospholipids, and free fatty acids in dam's milk, and in suckling rat lymph, portal plasma, vena cava plasma and liver; (2) Determination of positional distribution of fatty acids among the three different positions in triacylglycerols of milk, lymph, plasma and liver; (3) Isolation of plasma and mesenteric lymph lipoproteins by density gradient centrifugation, and identification of the individual classes of lipoproteins by measurement of their density and by polyacrylamide gel electrophoresis; (4) Determination of the concentration of each lipoprotein by refractometry and determination of the concentration and fatty acid composition of different lipid components in each lipoprotein fraction; (5) Studies of physical properties of the lipoproteins using analytical ultracentrifugation; (6) Determination of apoprotein composition and concentration in each lipoprotein fraction. The results show that the suckling rat consumes a diet which is rich in medium chain fatty acids (35% of total milk fatty acids). Mesenteric lymph triacylglycerols carry a significant amount of these medium chain fatty acids, unlike the adult in which they would be transported as free fatty acids, unlike the adult in which they would be transported as free fatty acids via the portal vein. Medium chain fatty acids are enriched at the sn-3 position in all triacylglycerols. Lymph contains chylomicrons, very low density lipoproteins, and high density lipoproteins, but no low density lipoproteins. Plasma contains all classes of lipoproteins but at concentrations higher than found in the adult, especially low density lipoproteins which are present at levels six times that found in the adult. The plasma very low density lipoproteins have a lipid composition which resembles that of chylomicron remnants. Apoprotein, lipid composition, and electrophoresis patterns show that the plasma lipoproteins in the suckling rat are heterogeneous.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Lipids -- Metabolism.; Rats -- Physiology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Biochemistry; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleLIPID ABSORPTION AND TRANSPORT IN THE SUCKLING RAT.en_US
dc.creatorFERNANDO, GERMAIN JITHENDRA.en_US
dc.contributor.authorFERNANDO, GERMAIN JITHENDRA.en_US
dc.date.issued1982en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe suckling rat obtains about 70% of its energy from the catabolism of lipid, compared to only about 25% in the adult rat. In addition, lipids are in great demand for membrane synthesis in the rapidly growing tissues. Thus the suckling rat represents an important system in which to study lipid metabolism. In this dissertation research the following experiments were performed on rats during the suckling period: (1) Determination of the concentration and fatty acid composition of triacylglycerols, cholesteryl esters, phospholipids, and free fatty acids in dam's milk, and in suckling rat lymph, portal plasma, vena cava plasma and liver; (2) Determination of positional distribution of fatty acids among the three different positions in triacylglycerols of milk, lymph, plasma and liver; (3) Isolation of plasma and mesenteric lymph lipoproteins by density gradient centrifugation, and identification of the individual classes of lipoproteins by measurement of their density and by polyacrylamide gel electrophoresis; (4) Determination of the concentration of each lipoprotein by refractometry and determination of the concentration and fatty acid composition of different lipid components in each lipoprotein fraction; (5) Studies of physical properties of the lipoproteins using analytical ultracentrifugation; (6) Determination of apoprotein composition and concentration in each lipoprotein fraction. The results show that the suckling rat consumes a diet which is rich in medium chain fatty acids (35% of total milk fatty acids). Mesenteric lymph triacylglycerols carry a significant amount of these medium chain fatty acids, unlike the adult in which they would be transported as free fatty acids, unlike the adult in which they would be transported as free fatty acids via the portal vein. Medium chain fatty acids are enriched at the sn-3 position in all triacylglycerols. Lymph contains chylomicrons, very low density lipoproteins, and high density lipoproteins, but no low density lipoproteins. Plasma contains all classes of lipoproteins but at concentrations higher than found in the adult, especially low density lipoproteins which are present at levels six times that found in the adult. The plasma very low density lipoproteins have a lipid composition which resembles that of chylomicron remnants. Apoprotein, lipid composition, and electrophoresis patterns show that the plasma lipoproteins in the suckling rat are heterogeneous.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectLipids -- Metabolism.en_US
dc.subjectRats -- Physiology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineBiochemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.proquest8303387en_US
dc.identifier.oclc683257030en_US
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