title: Extrarenal phenotypes of the UT-B knockout mouse.
abstract: The urea transporter UT-B is expressed in multiple tissues including erythrocytes, kidney, brain, heart, liver, colon, bone marrow, spleen, lung, skeletal muscle, bladder, prostate, and testis in mammals. Phenotype analysis of UT-B-null mice has confirmed that UT-B deletion results in a urea-selective urine-concentrating defect (see Chap. 9 ). The functional significance of UT-B in extrarenal tissues studied in the UT-B-null mouse is discussed in this chapter. UT-B-null mice present depression-like behavior with urea accumulation and nitric oxide reduction in the hippocampus. UT-B deletion causes a cardiac conduction defect, and TNNT2 and ANP expression changes in the aged UT-B-null heart. UT-B also plays a very important role in protecting bladder urothelium from DNA damage and apoptosis by regulating the urea concentration in urothelial cells. UT-B functional deficiency results in urea accumulation in the testis and early maturation of the male reproductive system. These results show that UT-B is an indispensable transporter involved in maintaining physiological functions in different tissues.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing, 100191, China, baoxue@bjmu.edu.cn.
authors.forename: Baoxue
authors.initials: B
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Lirong
authors.initials: L
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Meng
authors.forename: Zixun
authors.initials: Z
authors.lastname: Dong
authors.forename: Xuejian
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport / Q000235:genetics; D001921:Brain / Q000378:metabolism / Q000473:pathology; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D006329:Heart Conduction System / Q000002:abnormalities / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D018345:Mice, Knockout; D008957:Models, Genetic; D010641:Phenotype; D014508:Urea / Q000378:metabolism*; D001743:Urinary Bladder / Q000378:metabolism / Q000473:pathology
chemical_list: D026901:Membrane Transport Proteins; C452857:urea transporter B, mouse; D014508:Urea