Effect of Tolvaptan on Renal Plasma Flow (RPF) and Glomerular Filtration Rate (GFR) in ADPKD

Polycystic kidney disease (ADPKD) is a common genetic disorder, characterized by the formation of cysts in the kidneys, causing gradual renal function-loss. Previous studies have shown that, reduced glomerular filtration rate (GFR) and renal plasma flow (RPF) play a role in the progression of renal disease in ADPKD. Tolvaptan is a vasopressin 2 antagonist, which seems to reduce the growth of total kidney volume (TKV) and the decline in e-GFR in ADPKD. The mechanism is not fully understood and could, at least partly, be caused by stimulation of the renal blood flow. The purpose of this trial is to investigate if tolvaptan´s improve renal blood flow and glomerular filtration in ADPKD, in a randomized, cross-over, double-blind, placebo-controlled study.