 VA106483 is a selective vasopressin V2 receptor agonist which is currently under development for the treatment of nocturia in males. This study examines the pharmacological action of VA106483 on markers of clinical efficacy urine volumes and osmolality and safety markers coagulation factors and haemodynamics. The study will also assess the pharmacokinetics in the study population. The study design includes both cross-over and parallel phases so that pharmacodynamic and pharmacokinetic parameters can be assessed following both single and repeat dosing. Three dose levels will be given. 