title: Increase of Na/Pi-cotransport encoding mRNA in response to low Pi diet in rat kidney cortex.
abstract: Renal proximal Na/Pi-cotransport is increased in response to low dietary Pi intake. Recently, a cDNA (NaPi-2) related to the rat renal brush membrane Na/Pi-cotransporter has been cloned. In the present study, we used rats fed for 6 days with either a low Pi diet (LPD) or a high Pi diet (HPD), respectively. In parallel to an increased renal brush-border membrane Na/Pi-cotransport in LPD rats, there was also an increased content of NaPi-2 mRNA in renal cortex. After injection into Xenopus laevis oocytes, mRNA isolated from LPD rats induced a greater increase in Na/Pi-cotransport compared to mRNA from HPD rats. Hybrid depletion experiments suggested that mRNA-induced Na/Pi-cotransport is related to NaPi-2. We conclude that chronic Pi deprivation leads to an increased brush-border membrane Na/Pi-cotransport via an increase in the level of (NaPi-2) mRNA.
authors.affiliation: Department of Physiology, University of Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Werner
authors.forename: S A
authors.initials: SA
authors.lastname: Kempson
authors.forename: J
authors.initials: J
authors.lastname: Biber
authors.forename: H
authors.initials: H
authors.lastname: Murer
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000096:biosynthesis*; D015342:DNA Probes; D005260:Female; D015870:Gene Expression; D007672:Kidney Cortex / Q000378:metabolism*; D008297:Male; D008871:Microvilli / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D009865:Oocytes / Q000502:physiology; D010710:Phosphates / Q000172:deficiency* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters; D014982:Xenopus laevis / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D015342:DNA Probes; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010710:Phosphates; D012333:RNA, Messenger; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters