Urea transporter B (UT-B)

Urea transporter B (UT-B) is a membrane channel protein encoded by the SLC14A1 gene that facilitates the passive movement of urea across cell membranes. It is primarily expressed in erythrocytes and the descending vasa recta of the kidney, where it plays a vital role in the countercurrent exchange mechanism required for concentrated urine production. Beyond its renal functions, UT-B is found in the brain, heart, and colon, contributing to urea nitrogen salvaging and the regulation of cardiac conduction. As a therapeutic target, UT-B is being explored for the development of 'urearetics,' a novel class of sodium-sparing diuretics intended to treat fluid overload in conditions such as congestive heart failure and cirrhosis. These inhibitors work by disrupting the medullary urea gradient, leading to water loss without the electrolyte imbalances typically associated with conventional loop diuretics. Furthermore, SLC14A1 has been identified as a potential tumor suppressor and biomarker in several malignancies, including bladder and renal cancers.

Other names

Solute carrier family 14 member 1SLC14A1Kidd blood group antigenJKHUT11Urea transporter erythrocyteRACH1RACH2UT-B1

Inhibition of urea transport in the vasa recta and erythrocytes to disrupt the intrarenal urea gradient, inducing urea-selective diuresis (urearesis) without significant electrolyte loss.