Transport of amino acids and glucose in brush border membrane vesicles from the gills of the marine mussel, Mytilus edulis.

Persistent Link:
http://hdl.handle.net/10150/184462
Title:
Transport of amino acids and glucose in brush border membrane vesicles from the gills of the marine mussel, Mytilus edulis.
Author:
Pajor, Ana Marie.
Issue Date:
1988
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:
Marine mussels accumulate amino acids and glucose from seawater against considerable concentration gradients. The principal site for this uptake is the gill. Previous studies using intact, isolated gills from marine mussels have suggested that the transport mechanism involves coupling to Na⁺, similar to the mechanism of secondary active transport of amino acids and glucose in vertebrate epithelia, but until this dissertation there had been no rigorous test of this hypothesis. Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis, by differential and sucrose density centrifugation. The preparation procedure isolated a population of membranes enriched in brush border membrane markers. The transport of amino acids by two pathways, the alanine-lysine pathway (AK) and the alanine-proline pathway (AP), and the uptake of glucose was studied in the BBMV. The mechanism of transport through the three transport pathways is BBMV involved coupling to Na⁺. Concentrative uptake through the AK pathway, which transported alanine and lysine, also occurred in the presence of Li⁺ and K⁺ gradients. This pathway was the major route for alanine transport in BBMV. The AP pathway transported alanine and proline, and was strictly dependent on Na⁺. Glucose transport in gill BBMV resembled quite closely the Na⁺-coupled transport of glucose in vertebrate epithelia in such characteristics as Na⁺ and substrate specifically, and electrogenicity. Transport through the two amino acid uptake pathways (AK and AP) and through the glucose uptake pathway could be described by Michaelis-Menten kinetics, with high substrate affinities (K(t)'s below 10 μM). Furthermore, it is likely that multiple Na⁺ ions are involved in the transport of these amino acids and glucose in mussel gill BBMV. It appears that these transporters are adapted for function at low substrate concentrations and against large concentration gradients.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
MSH (Hormone); Pituitary hormones.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Physiology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Wright, Stephen H.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTransport of amino acids and glucose in brush border membrane vesicles from the gills of the marine mussel, Mytilus edulis.en_US
dc.creatorPajor, Ana Marie.en_US
dc.contributor.authorPajor, Ana Marie.en_US
dc.date.issued1988en_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.abstractMarine mussels accumulate amino acids and glucose from seawater against considerable concentration gradients. The principal site for this uptake is the gill. Previous studies using intact, isolated gills from marine mussels have suggested that the transport mechanism involves coupling to Na⁺, similar to the mechanism of secondary active transport of amino acids and glucose in vertebrate epithelia, but until this dissertation there had been no rigorous test of this hypothesis. Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis, by differential and sucrose density centrifugation. The preparation procedure isolated a population of membranes enriched in brush border membrane markers. The transport of amino acids by two pathways, the alanine-lysine pathway (AK) and the alanine-proline pathway (AP), and the uptake of glucose was studied in the BBMV. The mechanism of transport through the three transport pathways is BBMV involved coupling to Na⁺. Concentrative uptake through the AK pathway, which transported alanine and lysine, also occurred in the presence of Li⁺ and K⁺ gradients. This pathway was the major route for alanine transport in BBMV. The AP pathway transported alanine and proline, and was strictly dependent on Na⁺. Glucose transport in gill BBMV resembled quite closely the Na⁺-coupled transport of glucose in vertebrate epithelia in such characteristics as Na⁺ and substrate specifically, and electrogenicity. Transport through the two amino acid uptake pathways (AK and AP) and through the glucose uptake pathway could be described by Michaelis-Menten kinetics, with high substrate affinities (K(t)'s below 10 μM). Furthermore, it is likely that multiple Na⁺ ions are involved in the transport of these amino acids and glucose in mussel gill BBMV. It appears that these transporters are adapted for function at low substrate concentrations and against large concentration gradients.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectMSH (Hormone)en_US
dc.subjectPituitary hormones.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePhysiologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorWright, Stephen H.en_US
dc.contributor.committeememberWright, Ernest M.en_US
dc.contributor.committeememberWells, Michael A.en_US
dc.contributor.committeememberBurt, Janis M.en_US
dc.contributor.committeememberBraun, Eldon J.en_US
dc.identifier.proquest8822432en_US
dc.identifier.oclc701319655en_US
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