Assessment of Safety, Tolerability and Blood Concentrations of Single Doses of AZD3839 in Healthy Volunteers

Inclusion Criteria: * Healthy male and female volunteers of non-childbearing potential aged 18 to 55 years (inclusive) with suitable veins for cannulation or repeated venipuncture * Have a body mass index (BMI) between 19 and 30 kg/m2 (inclusive) and weigh between 50 kg and 100 kg (inclusive) * Creatinine clearance in the normal range (\>80 mL/min estimated according to Cockroft-Gault) * Healthy volunteers should have a serum potassium concentration of ≥3.8 mmol/L at screening (Visit 1) and on admission to the study centre (Day -1) * Clinically normal findings on physical examination in relation to age, as judged by the Investigator Exclusion Criteria: * History of any clinically significant disease or disorder which, in the opinion of the Investigator, may either put the healthy volunteer at risk because of participation in the study, or influence the results or the healthy volunteer's ability to participate in the study * History of psychotic disorder amongst first degree relatives * Significant orthostatic reaction at enrolment as judged by the Investigator * Prolonged QTcF greater than 450 msec or shortened QTcF less than 340 msec or family history of long QT syndrome or sudden death * Healthy volunteer is a vegetarian/lactose intolerant (exclusion criterion only applicable for healthy volunteers participating in Part 2