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The captopril challenge test (CCT) is a non-invasive medical test that measures the change in
renin
Renin (etymology and pronunciation), also known as an angiotensinogenase, is an aspartic protease protein and enzyme secreted by the kidneys that participates in the body's renin–angiotensin–aldosterone system (RAAS)—also known as the r ...
plasma-levels in response to administration of
captopril
Captopril, sold under the brand name Capoten among others, is an angiotensin-converting enzyme (ACE) inhibitor used for the treatment of hypertension and some types of congestive heart failure. Captopril was the first oral ACE inhibitor found ...
, an
angiotensin converting enzyme inhibitor
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. They work by causing relaxation of blood vessels as well as a decrease in blood volume ...
. It is used to assist in the diagnosis of
renal artery stenosis
Renal artery stenosis (RAS) is the narrowing of one or both of the renal arteries, most often caused by atherosclerosis or fibromuscular dysplasia. This narrowing of the renal artery can impede blood flow to the target kidney, resulting in renov ...
. It is not generally considered a useful test for children, and more suitable options are available for adult cases.
Procedure
Plasma concentration of renin is measured prior to and following the administration of captopril. The CCT is considered positive if the renin levels increase substantially or the baseline renin level is abnormally high. An abnormal captopril test is indicative of the presence of renovascular disease.
In adults
CCT in adults is known to have high
sensitivity
Sensitivity may refer to:
Science and technology Natural sciences
* Sensitivity (physiology), the ability of an organism or organ to respond to external stimuli
** Sensory processing sensitivity in humans
* Sensitivity and specificity, statisti ...
, but a low
specificity.
Subtraction angiography is considered a more suitable test for renal artery stenosis in adults.
[Svetkey LP, Himmelstein SI, Dunnick NR, Wilkinson RH Jr, Bollinger RR, McCann RL, Beytas EM, Klotman PE. Prospective analysis of strategies for diagnosing renovascular hypertension. Hypertension. 1989 Sep;14(3):247-57. .]
See also
*
Captopril suppression test
The captopril suppression test (CST) is a non-invasive medical test that measures plasma levels of aldosterone.
Aldosterone production is suppressed by captopril through the renin–angiotensin–aldosterone system. CST results are used to assis ...
- used to diagnose
primary aldosteronism
Primary aldosteronism (PA)'','' also known as primary hyperaldosteronism or Conn's syndrome, refers to the excess production of the hormone aldosterone from the adrenal glands, resulting in low renin levels and high blood pressure. This abnorm ...
References
{{Endocrine system procedures
Blood tests
Dynamic endocrine function tests