Figure 9. Decreased WNK1 abundance and SPAK/OSR1 activity in Sgk1^Pax8/LC1 KO mice.

(A) Inducible double-transgenic renal tubule–specific Sgk1^Pax8/LC1 KO mice or single-transgenic Sgk1^Pax8 or Sgk1^LC1 controls were treated with doxycycline and administered a low-NaCl diet. Total kidney lysates (50 μg) were analyzed by immunoblotting with the indicated antibodies. In the WNK1 exon 12 blot, full-length L-WNK1 (L) and lower-MW species (brackets) are shown. n = 5 Sgk1^Pax8/LC1 mice and 5 controls; P values as indicated, analyzed by Student’s t test with Welch’s correction. (B) Quantification of immunoblotting data in A. Control values were set to a mean of 100%, and actin-normalized densitometry values from Sgk1^Pax8/LC1 mice were expressed relative to the mean of the control.