Impaired Urea Accumulation in the Inner Medulla of Mice Lacking the Urea Transporter UT-A2

• DOI: 10.1128/mcb.25.16.7357-7363.2005
• Publication Date: 2005-07-29T19:27:50Z
• Authors: Shinichi Uchida; Eisei Sohara; Tatemitsu Rai; Masahito Ikawa; Masaru Okabe; Sei Sasaki
• Keywords: Medulla; Renal medulla

Urea transporter UT-A2, the major urea of thin descending limb loop Henle in short nephrons, has been implicated recycling medulla, thereby producing concentrated urine. To investigate physiological role UT-A2 vivo, we generated UT-A2-selective knockout mice by deleting promoter. Western analysis, immunohistochemistry, and quantitative reverse transcription-PCR were used to confirm specific deletion with preservation other UT-A transporters. Compared wild-type mice, differences urine outputs UT-A2−/− consuming a normal protein diet (20% protein) not observed under conditions or dehydration. Likewise, impairment accumulation inner medulla was observed. On low-protein (4% protein), however, significantly reduced maximal osmolality dehydrated compared littermates (2,500 mosmol versus 3,450 mosmol, respectively). A significant reduction also mice; Na+ Cl− Thus, is important for maintaining high concentration when supply kidney limited.