Intervention Study to Compare the Natriuretic Effects of Enalapril on Low and High Salt Diet

Sponsor

Georgetown University (Other)

Overall Status

Completed

CT.gov ID

NCT01324245

Collaborator

University of Virginia (Other)

Enrollment

Location

Arm

Duration (Months)

1.1

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Salt-sensitive Hypertension	Drug: Fenoldopam	N/A

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

Actual Enrollment :

45 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)

Official Title:

Paracrine Regulation of Renal Function by Dopamine in Normotensive Humans

Study Start Date :

Nov 1, 2002

Actual Primary Completion Date :

Dec 1, 2005

Actual Study Completion Date :

May 1, 2006

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Enalapril 2.5 mg every 12 hours for two doses	Drug: Fenoldopam Intravenous infusion at 0.5 mics/Kg/min for three hours Other Names: Enalaprilat Corlopam

Arm

Intervention/Treatment

Experimental: Enalapril

2.5 mg every 12 hours for two doses

Drug: Fenoldopam

Intravenous infusion at 0.5 mics/Kg/min for three hours

Other Names:

Enalaprilat

Corlopam

Outcome Measures

Primary Outcome Measures

Urinary sodium excretion [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 Outcome Measures

Renal Plasma Flow [During 3 hour fenoldopam infusion]
In order to explain physiologically the effects of fenoldopam on urinary sodium excretion on high and low salt diet, with and wothout enalapril, renal plasma flow was measured during the infusion using PAH clearance

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 55 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Volunteers
Healthy
Normal Blood Pressure

Exclusion Criteria:

Renal Impairment
Obesity
Salt sensitive increase in blood pressure

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Georgetown University Medical Center	Washington	District of Columbia	United States	20007

Sponsors and Collaborators

Georgetown University
University of Virginia

Investigators

Principal Investigator: Aruna R Natarajan, MD, PhD, Georgetown University Hospital
Study Director: Pedro A Jose, MD, PhD, Georgetown University/ George Washington University