Pharmacodynamic Effects of Dopamine Stratified by Race

The purpose of this investigation was to evaluate the effects of dopamine on heart rate (HR), systolic blood pressure (SBP), aldosterone, plasma renin activity (PRA), bradykinin, prolactin, corticotropin (ACTH), urinary output (UO), and urinary sodium (UNa) stratified by race. Sixteen healthy age- and weight-matched Caucasian and African American male subjects participated in this single-blind, three-phase study. The three phases included the following treatments and assessments: (i) 90-minute infusion of D(5)W 100 mL/h and control piggyback (control period); (ii) 90-minute infusion D(5)W 100 mL/h and 3 microg/kg/min dopamine (dopamine phase); (iii) assessments repeated 24 hours after dopamine administration (washout period). Plasma was analyzed for dopamine concentrations. Dopamine significantly increased HR and SBP across the study population. In addition, UO and UNa increased, prolactin was reversibly depressed, bradykinin and ACTH were unchanged, and aldosterone significantly rebounded on washout. With regard to race differences, SBP significantly increased in African Americans compared with Caucasians, and UNa significantly increased in Caucasians compared with African Americans. In summary, 3 microg/kg/min dopamine produced significant renal, hormonal, and hemodynamic changes in healthy men. Selected effects varied by race.