Essential role of vasopressin-regulated urea transport processes in the mammalian kidney.
Movement of urea across plasma membranes is modulated by specialized urea transporter proteins. Two urea-transporter genes have been cloned: UT-A (Slc14a2) and UT-B (Slc14a1). In the mammalian kidney, urea transporters are essential for the urinary concentrating mechanism and maintaining body fluid homeostasis. In this article, we discuss (1) an overview of historic discoveries in urea transport mechanisms; (2) an overview of recent discoveries in the regulation of urea transporters; (3) physiological studies in UT-A1/3 (-/-) mice highlighting the essential role of urea transporters in the urinary concentrating mechanism; and (4) physiological studies in UT-A2 and UT-B knockout mice examining the role of countercurrent exchange in the production of a maximally concentrated urine.
Fenton
Robert A
RA
The Water and Salt Research Center, Institute of Anatomy, University of Aarhus, Denmark. ROFE@ana.au.dk
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism; D001692:Biological Transport / Q000235:genetics; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007668:Kidney / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D010766:Phosphorylation; D017483:Receptors, Vasopressin / Q000378:metabolism; D054875:Ubiquitination; D014508:Urea / Q000378:metabolism*; D014667:Vasopressins / Q000502:physiology*; D000096982:Urea Transporters
D001127:Arginine Vasopressin; D026901:Membrane Transport Proteins; D017483:Receptors, Vasopressin; D014508:Urea; D014667:Vasopressins; D000096982:Urea Transporters; C452857:urea transporter B, mouse