Human peritoneal cells--a potential model for the study of cholesterol metabolism in macrophages.

Persistent Link:
http://hdl.handle.net/10150/185211
Title:
Human peritoneal cells--a potential model for the study of cholesterol metabolism in macrophages.
Author:
Winzerling, Joy Johnson.
Issue Date:
1990
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:
Studies of aortic plaque reveal the presence of tissue macrophages filled with cholesteryl esters. To study lipoprotein metabolism of in vivo, maturated human macrophages, I isolated cells from human peritoneal effluent. Population analysis using cytochemistry showed substantial numbers of acid-esterase positive monocytic cells, lymphocytes, leukocytes and erythrocytes. Substantial variation in cell populations existed among patients. Human peritoneal cells degraded low density lipoproteins (LDL) and acetylated LDL (AcLDL) by high affinity, receptor-mediated processes. AcLDL degradation saturated at 15 ug protein/ml and LDL degradation saturated at 11 ug protein/ml. Positive correlation of the percentages of monocytic cells with the degradation values (LDL, r =.710; AcLDL, r =.725) and a degradation assay using cells isolated by Lymphoprep showed that the monocytic cells substantially contributed to the degradation of LDL. AcLDL degradation was calcium independent and inhibited by fucoidin. LDL degradation was calcium dependent and very low density lipoprotein and apoE-containing high density lipoprotein (HDL) competed with LDL for receptor uptake; apoE-free HDL, AcLDL and fucoidin did not reduce LDL degradation. Both receptors were pronase-sensitive and degradation was dependent upon lysosomal activity. ACAT activity analysis showed that pre-incubation of cells with LDL or AcLDL stimulated ACAT activity. ACAT activity was greatest for cells preincubated using AcLDL and fresh medium was necessary to maintain the ACAT activity values beyond 24 hrs. LDL-stimulated ACAT activity declined as time was increased above 24 hrs. Flow cytometry analysis of a total cell population and the Lymphoprep-isolated cells revealed a heterogenous T cell population, the presence of monocyte/macrophages, suggested that some of the cells present were activated and confirmed cytochemistry analysis demonstrating that Lymphoprep concentrated the mononuclear cells. Human peritoneal macrophages formed foam cells when incubated in the presence of AcLDL or LDL for 72 hrs. The formation of foam cells in the presence of LDL was dependent upon cell exposure time to the medium. Foam cell formation in the presence of LDL was accompanied by dense vacuolization and in the demonstrated absence of the oxidation of LDL the oil red O stainable material collected outside the vacuoles.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Cholesterol -- Metabolism; Lipoproteins -- Metabolism; Macrophages; Atherosclerosis -- Etiology
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Nutritional Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
McNamara, Donald J.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleHuman peritoneal cells--a potential model for the study of cholesterol metabolism in macrophages.en_US
dc.creatorWinzerling, Joy Johnson.en_US
dc.contributor.authorWinzerling, Joy Johnson.en_US
dc.date.issued1990en_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.abstractStudies of aortic plaque reveal the presence of tissue macrophages filled with cholesteryl esters. To study lipoprotein metabolism of in vivo, maturated human macrophages, I isolated cells from human peritoneal effluent. Population analysis using cytochemistry showed substantial numbers of acid-esterase positive monocytic cells, lymphocytes, leukocytes and erythrocytes. Substantial variation in cell populations existed among patients. Human peritoneal cells degraded low density lipoproteins (LDL) and acetylated LDL (AcLDL) by high affinity, receptor-mediated processes. AcLDL degradation saturated at 15 ug protein/ml and LDL degradation saturated at 11 ug protein/ml. Positive correlation of the percentages of monocytic cells with the degradation values (LDL, r =.710; AcLDL, r =.725) and a degradation assay using cells isolated by Lymphoprep showed that the monocytic cells substantially contributed to the degradation of LDL. AcLDL degradation was calcium independent and inhibited by fucoidin. LDL degradation was calcium dependent and very low density lipoprotein and apoE-containing high density lipoprotein (HDL) competed with LDL for receptor uptake; apoE-free HDL, AcLDL and fucoidin did not reduce LDL degradation. Both receptors were pronase-sensitive and degradation was dependent upon lysosomal activity. ACAT activity analysis showed that pre-incubation of cells with LDL or AcLDL stimulated ACAT activity. ACAT activity was greatest for cells preincubated using AcLDL and fresh medium was necessary to maintain the ACAT activity values beyond 24 hrs. LDL-stimulated ACAT activity declined as time was increased above 24 hrs. Flow cytometry analysis of a total cell population and the Lymphoprep-isolated cells revealed a heterogenous T cell population, the presence of monocyte/macrophages, suggested that some of the cells present were activated and confirmed cytochemistry analysis demonstrating that Lymphoprep concentrated the mononuclear cells. Human peritoneal macrophages formed foam cells when incubated in the presence of AcLDL or LDL for 72 hrs. The formation of foam cells in the presence of LDL was dependent upon cell exposure time to the medium. Foam cell formation in the presence of LDL was accompanied by dense vacuolization and in the demonstrated absence of the oxidation of LDL the oil red O stainable material collected outside the vacuoles.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectCholesterol -- Metabolismen_US
dc.subjectLipoproteins -- Metabolismen_US
dc.subjectMacrophagesen_US
dc.subjectAtherosclerosis -- Etiologyen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineNutritional Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMcNamara, Donald J.en_US
dc.contributor.committeememberBerry, James W.en_US
dc.contributor.committeememberWeber, Charles W.en_US
dc.identifier.proquest9105916en_US
dc.identifier.oclc705002445en_US
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