Rapid Action of Aldosterone on Protein Levels of Sodium-Hydrogen Exchangers and Protein Kinase C Beta Isoforms in Rat Kidney.

Previous studies demonstrated that aldosterone rapidly activates sodium-hydrogen exchangers 1 and 3 (NHE 1 and 3). investigations revealed that protein kinase C (PKC) regulates NHE properties. We previously demonstrated that aldosterone rapidly enhances PKC protein abundance in the rat kidney. There are no reports of renal PKC (I and II) protein levels related to the regulation by aldosterone. There are also no data regarding the rapid effects of aldosterone on renal protein levels of NHE (1 and 3) and PKC (I and II), simultaneously. In the current study, rats received normal saline solution or aldosterone (150 g/kg BW, i.p.). After 30 minutes, abundance and immunoreactivity of these proteins were determined by Western blot analysis and immunohistochemistry, respectively. Aldosterone increased NHE1 and NHE3 protein abundance to 152% and 134%, respectively ( < 0.05). PKCI protein level was enhanced by 30%, whereas PKCII declined slightly. Aldosterone increased NHE protein expression mostly in the medulla. PKCI immunostaining intensity was increased in the glomeruli, renal vasculature, and thin limb of the loop of Henle, while PKCII was reduced. This is the first study to simultaneously demonstrate that aldosterone rapidly elevates PKCI and NHE (1 and 3) protein abundance in the rat kidney. Aldosterone-induced NHE (1 and 3) protein levels may be related to PKCI activation.