Paracrine Regulation of Renal Function by Dopamine in Normotensive Humans
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Georgetown University
- Enrollment
- 45
- Locations
- 1
- Primary Endpoint
- Urinary sodium excretion
Study Overview
Brief Summary
The kidney plays a crucial role in maintaining salt balance by two opposing physiological mechanisms: the renal dopaminergic system which enhances salt excretion and the renin-angiotensin system (RAS) which causes salt retention. Salt-sensitive hypertension occurs when this balance is altered or abnormal. We hypothesized that this balance is influenced by salt intake: therefore dietary salt affects the natriuretic response to the renal dopaminergic agonist Fenoldopam, and the Angiotensin Converting Enzyme inhibitor, Enalapril.
In this trial we study normal salt balance mechanisms in salt resistant adults with normal blood pressure.
Detailed Description
Eight adults of both genders and all races were studied in this double blind placebo controlled cross over study with randomization of the order of interventions. After 5 days each on low salt (about 1 gram/day) and high salt (about 6 grams/day)diet, with a washout period of at least four weeks in between, every subject was treated with Enalapril and Placebo on two consecutive days, followed by a Fenoldopam infusion for three hours, during which natriuresis and renal function testing were performed.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Masking
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 55 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Volunteers
- •Normal Blood Pressure
Exclusion Criteria
- •Renal Impairment
- •Salt sensitive increase in blood pressure
Arms & Interventions
Enalapril
2.5 mg every 12 hours for two doses
Intervention: Fenoldopam (Drug)
Outcomes
Primary Outcomes
Urinary sodium excretion
Time Frame: During the trial: a 3 hour fenoldopam infusion
All subjects received placebo/enalapril in a randomized counterbalanced fashion in both phases. Phase 1 was on low salt, while Phase 2 was on high salt. All subjects received a 3 hour fenoldopam infusion, during which time urinary sodium excretion was measured as the primary outcome bvariable.
Secondary Outcomes
- Renal Plasma Flow(During 3 hour fenoldopam infusion)