A urea transporter is a membrane transport protein, transporting urea. Humans and other mammals have two types of urea transport proteins, UT-A and UT-B. The UT-A proteins are important for renal urea handling and are produced by alternative splicing of the SLC14A2 gene. Urea transport in the kidney is regulated by vasopressin. Urea transporters can be inhibited by the action of urea analogues like thiourea and glycosides like phloretin. Their inhibition results in increased diuresis due to urea induced osmosis in the collecting ducts of the kidney.