Abstract
Concentration of urine in mammals is regulated by the antidiuretic hormone vasopressin. Binding of vasopressin to its V2 receptor leads to the insertion of water channels in apical membranes of principal cells in collecting ducts. In nephrogenic diabetes insipidus (NDI), the kidney fails to concentrate urine in response to vasopressin. A male patient with an autosomal recessive form of NDI was found to be a compound heterozygote for two mutations in the gene encoding aquaporin-2, a water channel. Functional expression studies in Xenopus oocytes revealed that each mutation resulted in nonfunctional water channel proteins. Thus, aquaporin-2 is essential for vasopressin-dependent concentration of urine.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Aquaporin 2
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Aquaporin 6
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Aquaporins*
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Base Sequence
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Cloning, Molecular
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Deamino Arginine Vasopressin / pharmacology*
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Diabetes Insipidus / genetics*
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Diabetes Insipidus / physiopathology
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Female
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Genes, Recessive
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Heterozygote
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Humans
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Kidney / metabolism
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Kidney / physiology*
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Kidney Concentrating Ability*
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Male
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Membrane Proteins / chemistry
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Membrane Proteins / genetics
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Membrane Proteins / physiology*
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Molecular Sequence Data
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Oocytes
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Pedigree
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Point Mutation
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Protein Structure, Secondary
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RNA, Complementary / genetics
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Water / metabolism
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Xenopus laevis
Substances
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AQP2 protein, human
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Aquaporin 2
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Aquaporin 6
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Aquaporins
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Membrane Proteins
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RNA, Complementary
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Water
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Deamino Arginine Vasopressin