P-363: Protein abundance of renal Na transporters in femal mice lacking type1A angiotensin II receptor

The type 1 angiotensin II receptor (AT1R) antagonist, losartan, lowers blood pressure in humans and rodents with hypertension by several mechanisms, including a decrease in renal sodium transport. In order to determine how AT1R participates in the regulation of renal Na transpsort, we measured the protein abundance (immunoblotting) of Na transporters expressed in the kidney of AT1A receptor deficient mice. Six pairs of AT1A deficient mice (KO) and their wild type (WT) littermates (female, 4-6 months old) were fed 0.4% Na diet with ad libitum water and food intake. The proximal tubule and thick ascending limb Na transporter, NHE3, was decreased in KO mice (WT: 100±8%, KO: 47±8%, corrected for protein loading and expressed as mean ± SE percentage of WT set at 100%, *P