Linked Life Data

10516278

Source:http://linkedlifedata.com/resource/pubmed/id/10516278

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 2
pubmed:dateCreated
1999-11-17
pubmed:abstractText
The aim of the present study was to characterize the type(s) of NaPO(4) cotransporter expressed in the human renal cell line HEK-293 and its regulation by parathyroid hormone (PTH) in wild-type cells and in cells transfected by the PTH/PTH-related protein (PTHrP) receptor. The results showed that human embryonic kidney HEK-293 cells expressed NaPO(4) cotransporter type III (PiT1) mRNA and protein. In contrast, type I (NPT1) or II (NPT2) cotransporter mRNA were not expressed. Na(+)-dependent phosphate uptake followed a Michaelis-Menten model (apparent maximal transport rate and affinity constant: 23.32 +/- 0.69 nmol PO(4). mg protein(-1). 10 min(-1) and 0.147 +/- 0.014 mM KH(2)PO(4), respectively), was stimulated by phosphate deprivation (maximal increase 24.5 +/- 0.8%, P < 0.001, after 15 h of phosphate deprivation), and was inhibited by increasing pH (3.6 +/- 0.2-fold decrease at pH 8.5, P < 0.0001). It was inhibited in a time- and concentration-dependent fashion by PTH in HEK-293 cells stably transfected by PTH/PTHrP receptors but not in parental HEK-293 cells. Maximal inhibition of Na(+)-dependent phosphate transport was observed at 30 min after the addition of 72 nM PTH-(1-34) (31.5 +/- 2.4% inhibition, P < 0.01). PTH inhibition of phosphate transport was maintained in phosphate-deprived cells and reversed by both GF109203X (10(-6) M) or staurosporine (5.5 nM), two protein kinase C inhibitors. Na(+)-dependent phosphate uptake was also significantly inhibited by phorbol 12-myristate 13-acetate (20.9 +/- 3.9% inhibition, P < 0.001) but not by dibutyril-cAMP (10(-4) M) or forskolin (50 microM). The physiological role played by type III NaPO(4) cotransport expression in the overall renal regulation of phosphate homeostasis remains to be established.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F543-51
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10516278-Biological Transport, pubmed-meshheading:10516278-Carrier Proteins, pubmed-meshheading:10516278-Cell Line, pubmed-meshheading:10516278-Embryo, Mammalian, pubmed-meshheading:10516278-Humans, pubmed-meshheading:10516278-Hydrogen-Ion Concentration, pubmed-meshheading:10516278-Kidney, pubmed-meshheading:10516278-Kinetics, pubmed-meshheading:10516278-Parathyroid Hormone, pubmed-meshheading:10516278-Phosphates, pubmed-meshheading:10516278-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:10516278-Sodium-Phosphate Cotransporter Proteins, pubmed-meshheading:10516278-Sodium-Phosphate Cotransporter Proteins, Type I, pubmed-meshheading:10516278-Sodium-Phosphate Cotransporter Proteins, Type III, pubmed-meshheading:10516278-Symporters, pubmed-meshheading:10516278-Time Factors
pubmed:year
1999
pubmed:articleTitle
NaPO(4) cotransport type III (PiT1) expression in human embryonic kidney cells and regulation by PTH.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine Xavier Bichat, 75018 Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't