Brattleboro rats have impaired apical membrane water permeability regulation in the outer medullary collecting duct principal cells.
Vasopressin (AVP) regulates the body salt-water balance. Brattleboro rats carry an AVP gene mutation resulting in a recessive form of central diabetes insipidus, being ideal for AVP deficiency studies. Herein, we studied the water permeability of the apical and basolateral sides of outer medullary collecting duct (OMCD) principal cells in response to dDAVP (a V2 receptor agonist) administration in Wistar and Brattleboro rats. Biophysical measurements of the water permeability (Pf) of isolated OMCD principal cells were performed with the calcein quenching method with/without dDAVP (10-8mol/L). mRNA transcripts and protein levels of AQP2, AQP3 and AQP4 were assessed by RT-PCR and western blot respectively. dDAVP increased the apical and basolateral Pfof OMCD principal cells in Wistar rats, while in Brattleboro rats this effect was present basolaterally. Long-term dDAVP administration in both strains resulted in a significant increase in mRNA expression of all assessed AQP's while only the protein levels of AQP2 and AQP3 were significantly increased. Short-term (20 minutes) dDAVP treatment of isolated OMCD fragments resulted in significantly increased plasma membrane expression of AQP2 in Wistar rats and of AQP2 and AQP3 in Brattleboro rats. In summary, dDAVP induces different expression of AQP2, AQP3 and AQP4 in Wistar and Brattleboro rats during short- and long-term treatment. In Wistar rats dDAVP mainly increased AQP2 expression while in Brattleboro rats it increased functional water permeability mainly by AQP3 expression.
Institute of Cytology and Genetics, SB RAS, Novosibirsk, Russia.
Galina S
GS
Baturina
Institute of Cytology and Genetics, SB RAS, Novosibirsk, Russia.
Liubov E
LE
Katkova
Department of Physiology, Faculty of Medicine, University of Thessaly, BIOPOLIS, Larissa, Greece.
Sotirios G
SG
Zarogiannis
Institute of Cytology and Genetics, SB RAS, Novosibirsk, Russia.|Novosibirsk State University, Novosibirsk, Russia.
Evgeniy I
EI
Solenov
D000818:Animals; D020346:Aquaporins / Q000096:biosynthesis; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D007679:Kidney Medulla / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007685:Kidney Tubules, Collecting / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D010539:Permeability / Q000187:drug effects; D051381:Rats; D011910:Rats, Brattleboro; D017208:Rats, Wistar; D014867:Water / Q000008:administration & dosage / Q000378:metabolism*
D020346:Aquaporins; D014867:Water; D003894:Deamino Arginine Vasopressin
Brattleboro rats; aquaporins; dDAVP; principal cells; vasopressin