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Sponsors and Collaborators: |
University of Virginia National Institutes of Health (NIH) |
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Information provided by: | University of Virginia |
ClinicalTrials.gov Identifier: | NCT00592150 |
Hypothesis to be tested: Dopamine D1-like receptor-induced natriuresis is impaired in humans with G protein-related kinase 4 gene variants.
Our research group has discovered a D1 receptor/adenylyl cyclase coupling defect in renal PTCs from subjects with essential hypertension. We have found increased GRK-4 activity in renal PTCs in human essential hypertension due to activating variants of GRK-4, an effect that was reproduced in a transfected cell model. Preventing the translation of GRK-4 normalized the coupling of the D1 receptor to adenylyl cyclase in hypertension. Gene variants of GRK-4 cause a ligand-independent serine-phosphorylation of the D1 receptor, resulting in its uncoupling from the G-protein/effector complex.
The desensitization of the D1 receptor in the renal PTC is hypothesized to be the cause of the compromised natriuretic effect of DA that eventually leads to Na+ retention and hypertension. The primary objective of this protocol is to demonstrate that natriuresis engendered by D1-like receptor activation with fenoldopam is blunted in subjects with 3 or more SNPs of GRK-4 compared with responses in subjects with 0-2 SNPs.
Condition | Intervention | Phase |
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Hypertension |
Drug: fenoldopam Drug: Placebo |
Phase I |
Study Type: | Interventional |
Study Design: | Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Crossover Assignment, Safety/Efficacy Study |
Official Title: | Effect of Gene Variants on Dopamine Receptor Natriuretic Responses (RMC033) |
Estimated Enrollment: | 44 |
Study Start Date: | June 2007 |
Estimated Study Completion Date: | June 2010 |
Estimated Primary Completion Date: | June 2009 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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1: Experimental
Fenoldopam infusion
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Drug: fenoldopam
The fenoldopam infusion rate will be 0.05 μg/kg/min for 3 hours
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2: Placebo Comparator
Placebo infusion
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Drug: Placebo
Placebo infusion for 3 hours
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Ages Eligible for Study: | 18 Years to 70 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Normotensive (NT) Subjects
Hypertensive (HT) Subjects
Exclusion Criteria:
United States, Virginia | |
University of Virginia | |
Charlottesville, Virginia, United States, 22903 |
Principal Investigator: | Robert M Carey, MD | University of Virginia |
Responsible Party: | University of Virginia ( Robert Carey, MD ) |
Study ID Numbers: | 13072 |
Study First Received: | December 27, 2007 |
Last Updated: | August 6, 2008 |
ClinicalTrials.gov Identifier: | NCT00592150 History of Changes |
Health Authority: | United States: Institutional Review Board |
Essential Hypertension |
Neurotransmitter Agents Vasodilator Agents Essential Hypertension Dopamine Fenoldopam Vascular Diseases |
Dopamine Agents Cardiovascular Agents Dopamine Agonists Antihypertensive Agents Hypertension |
Vasodilator Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Physiological Effects of Drugs Vascular Diseases Cardiovascular Agents Antihypertensive Agents |
Dopamine Agonists Pharmacologic Actions Therapeutic Uses Fenoldopam Cardiovascular Diseases Dopamine Agents Hypertension |