The X-linked Hyp mutation is characterized by a specific defect in phosphate (Pi) transport at the renal brush-border membrane (BBM). To understand the mechanism for the 50% decrease in Vmax of the high affinity Pi transport system in BBM of Hyp mice, we compared the effects of external Na$ sp+$ concentration, membrane potential, external pH, and Pi transport inhibitors on Pi uptake in BBM vesicles (BBMV) prepared from normal mice and Hyp littermates. / The apparent affinity for Na$ sp+$, the Na$ sp+{:}$Pi stoichiometry, the response to membrane potential and the response to external pH are similar in BBMV from both normals and mutants. / The Ki for phosphonoformic acid (PFA) inhibition of Na$ sp+$-Pi cotransport is lower in BBMV prepared from Hyp mice when compared to normal mice but not different in BBMV from Pi-deprived mice which are characterized by an increase in Vmax of the high affinity Na$ sp+$-Pi cotransport system. / We conclude that the decrease in Vmax of the high affinity Na$ sp+$-Pi cotransport system in the Hyp mouse is not the result of an inappropriate response of the transport system to Na$ sp+$, membrane potential or pH.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.61173 |
| Date | January 1991 |
| Creators | Harvey, Natalie |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001274620, proquestno: AAIMM74847, Theses scanned by UMI/ProQuest. |
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