Ignite Creation Date:
2024-05-05 @ 11:55 AM
Last Modification Date:
2024-10-26 @ 9:16 AM
Study NCT ID:
NCT00173446
Status:
UNKNOWN
Last Update Posted:
2007-06-08
First Post:
2005-09-12
Brief Title:
D2 Dopamine Receptor on Human Aldosterone-Producing Adenoma and Its Role in Aldosterone Secretion and Cell Proliferation
Sponsor:
National Taiwan University Hospital
Organization:
National Taiwan University Hospital
Study Overview
Official Title:
Expression of D2-Like Dopamine Receptor of Human Aldosterone-Producing Adenoma and Its Role in Regulation of Aldosterone Secretion and Cell Proliferation
Status:
UNKNOWN
Status Verified Date:
2005-08
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
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
Detailed Description:
None
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None