title: Expression of urea transporter (UT-A) mRNA in papilla and pelvic epithelium of kidney in normal and low protein fed sheep.
abstract: The identification and cloning of the urea transporter (UT) in papilla and upper pelvic epithelium of sheep kidney and the effect of a 5-week-lasting low protein diet on UT mRNAs expression in these structures are reported. Using degenerate primers we cloned by RT-PCR a 770-base pairs UT-A cDNA fragment. The deduced amino acid sequence shared 92% and 93% identity with UT-A2 protein from rabbit and rat, and from human, respectively. Quantification of UT-A mRNAs expression after LP diet was performed by quantitative RT-PCR using UT-A mutant cRNA. Compared to normal protein fed sheep, low protein diet was associated with a significant reduction of UT-A mRNA levels in pelvic epithelium (852+/-172 vs. 2024+/-260 molecules, P<0.01) and a tendency to its increase in papilla (7959+/-1741 vs. 5447+/-1040 molecules, NS). Functional studies confirmed that kidneys of low protein fed sheep increased their ability to reduce urea losses. The reduction of UT-A expression in the pelvic epithelium lining the outer medulla could be relevant for the renal conservation of urea in protein restricted sheep.
authors.affiliation: Departamento Básico de Medicina, Facultad de Medicina, 11800 Montevideo, Uruguay.
authors.forename: Nora
authors.initials: N
authors.lastname: Artagaveytia
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Elalouf
authors.forename: Christian
authors.initials: C
authors.lastname: de Rouffignac
authors.forename: Robert
authors.initials: R
authors.lastname: Boivin
authors.forename: Alberto
authors.initials: A
authors.lastname: Cirio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology*; D004848:Epithelium / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D007679:Kidney Medulla / Q000187:drug effects* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010388:Pelvis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D034561:Sheep, Domestic / Q000235:genetics* / Q000378:metabolism; D000096982:Urea Transporters
chemical_list: D004044:Dietary Proteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D000096982:Urea Transporters