- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT00173446
D2 Dopamine Receptor on Human Aldosterone-Producing Adenoma and Its Role in Aldosterone Secretion and Cell Proliferation
June 7, 2007 updated by: National Taiwan University Hospital
Expression of D2-Like Dopamine Receptor of Human Aldosterone-Producing Adenoma and Its Role in Regulation of Aldosterone Secretion and Cell Proliferation
Dopamine (DA) is one of the main catecholamines in mammals.
Its major role as a brain neurotransmitter is well known as well as its contribution to the development of pathologies, mainly arterial hypertension.
Traditionally, dopamine receptors are divided into two families according to the stimulation or inhibition they may produce at the adenyl cyclase level.
Five dopamine receptors have been identified: D1 (D1a) and D5 (D1b) exist in the D1 family.
D2s, D2l, D3 and D4 belong to the D2 family.
Formerly, less than 1% of patients with hypertension were believed to have primary hyperaldosteronism; however, recent studies have suggested that primary aldosteronism affects 5-13% of patients with hypertension and aldosteronomas are a more common cause of hypertension than previously thought.
At least 2% of patients with hypertension may have an aldosteronoma.
The investigators' previous clinical observation found two subtypes of aldosterone-producing adenoma (APA), which were defined according to their responses to metoclopramide during salt manipulation.
On a high-salt diet (HS), the nonsuppressible subjects, with less dopaminergic inhibition of aldosterone secretion, had less urinary DA excretion and greater blood pressure (BP) elevation [Wu KD et al. 2002].
The investigators' recent study of six patients with an APA found that the expression of the D2 receptor in APA was not universal.
The amounts of D2 receptor messenger ribonucleic acid (mRNA) were more variant in either APA or their remnant adrenal glands.
Only two cases of APA expressed the D2 receptors with much weaker signals compared with those in their respective remnant adrenals [Wu KD et al. 2001].
The investigators' current work demonstrates that the D2 receptor negatively regulates AII-stimulated aldosterone secretion and aldosterone synthase mRNA expression in NCI-H295R cells.
On the other hand, the D4 receptor counteracts with the effect of the D2 receptor.
In a future study, the investigators wish to quantify D2 and D4 receptor mRNA and protein expression in APA and their remnant adrenal glands and correlate them to their clinical metoclopramide test results.
The investigators also wish to know whether the difference between the D2 and D4 receptor expression reflect the different effects of dopamine inhibition on AII-stimulated aldosterone secretion and aldosterone synthase transcription.
Finally, the investigators will explore the role of D2 and D4 receptors on AII-stimulated adrenal cell proliferation.
Study Overview
Status
Unknown
Study Type
Observational
Enrollment (Anticipated)
30
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Contact
- Name: Hong-Wei Chang
- Phone Number: 5762 886223123456
- Email: chianghongwei@yahoo.com.tw
Study Locations
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Taipei, Taiwan, 100
- Recruiting
- National Taiwan University Hospital
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Contact:
- Hong-Wei Chang
- Phone Number: 5762 886223123456
- Email: chianghongwei@yahoo.com.tw
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-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
- Child
- Adult
- Older Adult
Accepts Healthy Volunteers
No
Genders Eligible for Study
All
Description
Inclusion Criteria:
- Adrenal aldosterone-producing adenoma
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Investigators
- Principal Investigator: Hong-Wei Chang, National Taiwan University Hospital
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start
January 1, 2002
Study Registration Dates
First Submitted
September 12, 2005
First Submitted That Met QC Criteria
September 12, 2005
First Posted (Estimate)
September 15, 2005
Study Record Updates
Last Update Posted (Estimate)
June 8, 2007
Last Update Submitted That Met QC Criteria
June 7, 2007
Last Verified
August 1, 2005
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- 9461700673
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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