Vasopressin Alters the Expression of Aquaporins, Urea Transporters, and ER Stress Genes in the Mouse Renal Medulla

Abstract

Vasopressin, an antidiuretic hormone (ADH), plays an essential role in water regulation during dehydration. The purpose of this study is to examine novel genes that may be activated by vasopressin and evaluate the relative expression of several proteins in the renal collecting duct. 48 hours after water restriction measurements confirmed the increased expression of mRNA of AQP2, AQP3 and the ER stress genes AR, ATF3, and GRP78 .We found that water restriction increases the expression of AQP2 and AQP3 proteins to 1.88 ± 0.08 fold vs. control 1.00 ± 0.14 fold and 2.88 ± 0.33 fold vs. control 1.00 ± 0.16 fold, respectively. Water restriction increases the expression of AR and ATF3 proteins to 1.33 ± 0.14 fold vs. control 1.00 ± 0.13 fold and 3.81 ± 0.24 fold vs. control 1.00 ± 0.06 fold, respectively. There was an increased mRNA expression of GRP78 with 1.43 ± 0.11 fold vs. control 1.00 ± 0.04 fold. Vasopressin implantation increases in the mRNA abundance of AQP2 and AQP3 proteins to 1.88 ± 0.09 fold vs. control 1.00 ± 0.07 fold and 1.46 ± 0.04 fold vs. control 1.00 ± 0.15 fold, respectively. Vasopressin implantation increases in the mRNA abundance of UTA-1 and UTA-3 proteins to 1.88 ± 0.11 fold vs. control 1.00 ± 0.02 fold 1.94 ± 0.4 fold vs. control 1.00 ± 0.2 fold, respectively. There was a significant increase in the mRNA abundance of ATF3 2.75 ± 0.55 4 fold vs. control 1.00 ± 0.31 fold as well as CHOP10 to 1.7 ± 0. 4 fold vs. control 1.00 ± 0.09 fold in the renal medulla. Insights on these genes are important as vasopressin levels are high in diseases such as diabetes and congestive heart failure.