Abstract | BACKGROUND: METHODS: Female rats were investigated 2 weeks after induction of DM by streptozotocin administration. Kidneys were examined by immunohistochemisty and semiquantitative immunoblotting. RESULTS: We demonstrated that the protein expression of renal AQP2, Ser-256 phosphorylated AQP2, AQP3, beta- and gamma-ENaC (but not alpha-ENaC) increased consistently with an increased AVP response. In contrast, there were no significant changes in the relative apical targeting of beta-, gamma- and alpha-ENaC, and the shift in the molecular weight of gamma-ENaC from 85 kDa to 70 kDa was not observed despite increased plasma aldosterone levels. These results were supported by changes in the functional data showing increased solute-free water reabsorption, increased fractional excretion of sodium and an unchanged ratio of potassium to sodium in the urine. CONCLUSIONS: The data demonstrate that diabetic kidneys have a reduced sensitivity to the anti-natriuretic action of elevated plasma aldosterone levels with no relative increase in ENaC subunit apical targeting, whereas there is increased expression of beta- and gamma-ENaC, which alone may play a role in the increased sodium reabsorption in the kidney in DM.
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Authors | Heidi O'Neill, Janne Lebeck, Patrick B Collins, Tae-Hwan Kwon, Jørgen Frøkiaer, Søren Nielsen |
Journal | Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association
(Nephrol Dial Transplant)
Vol. 23
Issue 5
Pg. 1546-55
(May 2008)
ISSN: 1460-2385 [Electronic] England |
PMID | 18029369
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Aqp2 protein, rat
- Aqp3 protein, rat
- Aquaporin 2
- Epithelial Sodium Channels
- Protein Subunits
- Arginine Vasopressin
- Aquaporin 3
- Aldosterone
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Topics |
- Aldosterone
(blood, metabolism)
- Animals
- Aquaporin 2
(metabolism)
- Aquaporin 3
(metabolism)
- Arginine Vasopressin
(blood, metabolism)
- Diabetes Mellitus, Experimental
(blood, metabolism)
- Diabetic Nephropathies
(blood, metabolism)
- Epithelial Sodium Channels
(chemistry, metabolism)
- Female
- Immunohistochemistry
- Kidney
(metabolism)
- Natriuresis
- Protein Subunits
- Rats
- Rats, Wistar
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