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Downregulation of aquaporin-2 and -3 in aging kidney is independent of V(2) vasopressin receptor.
- Source :
-
American journal of physiology. Renal physiology [Am J Physiol Renal Physiol] 2000 Jul; Vol. 279 (1), pp. F144-52. - Publication Year :
- 2000
-
Abstract
- The mechanisms underlying age-related polyuria were investigated in 10- and 30-mo-old female WAG/Rij rats. Urinary volume and osmolality were 3.9 +/- 0.3 ml/24 h and 2,511 +/- 54 mosmol/kgH(2)O in adult rats and 12.8 +/- 0.8 ml/24 h and 1,042 +/- 44 mosmol/kgH(2)O in senescent animals. Vasopressin V(2) receptor mRNA did not significantly differ between 10 and 30 mo, and [(3)H]vasopressin binding sites in membrane papilla were reduced by 30%. The cAMP content of the papilla was unchanged with age, whereas papillary osmolality was significantly lowered in senescent animals. The expression of aquaporin-1 (AQP1) and -4 was mostly unaltered from 10 to 30 mo. In contrast, aquaporin-2 (AQP2) and -3 (AQP3) expression was downregulated by 80 and 50%, respectively, and AQP2 was markedly redistributed into the intracellular compartment, in inner medulla of senescent animals, but not in renal cortex. These results indicate that age-related polyuria is associated with a downregulation of AQP2 and AQP3 expression in the medullary collecting duct, which is independent of vasopressin-mediated cAMP accumulation.
- Subjects :
- Animals
Aquaporin 2
Aquaporin 3
Aquaporin 6
Binding Sites
Body Weight
Cell Membrane metabolism
Cyclic AMP metabolism
Drinking
Eating
Female
Fluorescent Antibody Technique, Indirect
Kidney pathology
Kidney physiopathology
Kidney ultrastructure
Kidney Medulla metabolism
Kidney Medulla pathology
Kidney Medulla physiopathology
Kidney Medulla ultrastructure
Kidney Tubules metabolism
Kidney Tubules pathology
Kidney Tubules physiopathology
Kidney Tubules ultrastructure
Osmolar Concentration
Polyuria pathology
Polyuria physiopathology
RNA, Messenger genetics
RNA, Messenger metabolism
Rats
Rats, Inbred Strains
Receptors, Vasopressin genetics
Vasopressins metabolism
Aging physiology
Aquaporins metabolism
Down-Regulation
Kidney metabolism
Polyuria metabolism
Receptors, Vasopressin metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1931-857X
- Volume :
- 279
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Renal physiology
- Publication Type :
- Academic Journal
- Accession number :
- 10894796
- Full Text :
- https://doi.org/10.1152/ajprenal.2000.279.1.F144