Urea transporter A and B (SLC14A1 and SLC14A2) (UT-A/UT-B)

Urea transporters UT-A and UT-B are integral membrane proteins belonging to the solute carrier family 14 (SLC14) that facilitate the passive movement of urea across biological membranes (UniProt, Q13336, Q15848). UT-A isoforms, encoded by the SLC14A2 gene, are predominantly expressed in the renal inner medullary collecting duct and the thin descending limb of Henle's loop, where they are essential for the urinary concentrating mechanism (PubMed, PMID: 21930148). UT-B, encoded by the SLC14A1 gene, is found in the vasa recta and red blood cells, facilitating urea countercurrent exchange to maintain the medullary osmotic gradient (NIH, PMC3189314). These transporters are significant therapeutic targets for the development of 'urearetics,' a novel class of diuretics that promote water excretion without the electrolyte imbalances typically associated with loop diuretics (PubMed, PMID: 24509434). By inhibiting UT-A and UT-B, these compounds disrupt the intrarenal urea recycling process, thereby reducing the kidney's ability to concentrate urine and treating conditions such as congestive heart failure and cirrhosis-related edema (PubMed, PMID: 29108052).

Other names

Solute carrier family 14 member 1Solute carrier family 14 member 2Kidd blood group antigenHUT11UT1UT2Urea transporter 1Urea transporter 2

Inhibition of facilitated urea transport across cell membranes in the renal medulla, which disrupts the intrarenal urea gradient and reduces the osmotic driving force for water reabsorption, leading to urearesis (PubMed, PMID: 24509434).