| Captopril suppression test | |
|---|---|
 Aldosterone (chemical structure) is measured in the CST. | |
| Purpose | measures plasma levels of aldosterone. |
The captopril suppression test (CST) is a non-invasive medical test that measures plasma levels of aldosterone. [1] Aldosterone production is suppressed by captopril through the renin–angiotensin–aldosterone system. CST results are used to assist in the diagnososis of primary aldosteronism (Conn Syndrome).
Aldosterone is the main mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon. It plays a central role in the homeostatic regulation of blood pressure, plasma sodium (Na+), and potassium (K+) levels. It does so primarily by acting on the mineralocorticoid receptors in the distal tubules and collecting ducts of the nephron. It influences the reabsorption of sodium and excretion of potassium (from and into the tubular fluids, respectively) of the kidney, thereby indirectly influencing water retention or loss, blood pressure and blood volume. When dysregulated, aldosterone is pathogenic and contributes to the development and progression of cardiovascular and kidney disease. Aldosterone has exactly the opposite function of the atrial natriuretic hormone secreted by the heart.
CST or Cst may refer to:
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 abnormality is caused by hyperplasia or tumors. Many suffer from fatigue, potassium deficiency and high blood pressure which may cause poor vision, confusion or headaches. Symptoms may also include: muscular aches and weakness, muscle spasms, low back and flank pain from the kidneys, trembling, tingling sensations, dizziness/vertigo, nocturia and excessive urination. Complications include cardiovascular disease such as stroke, myocardial infarction, kidney failure and abnormal heart rhythms.
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 for the treatment of hypertension. Unlike beta-blockers, another class of drugs used to treat angina and hypertension, Captopril does not generally impair intellectual or sexual functions. It also does not cause fatigue as associated with beta-blockers. Due to the adverse drug event of causing hyperkalemia, as seen with most ACE Inhibitors, the medication is usually paired with a diuretic.
Hypoaldosteronism is an endocrinological disorder characterized by decreased levels of the hormone aldosterone. Similarly, isolated hypoaldosteronism is the condition of having lowered aldosterone without corresponding changes in cortisol.
The zona glomerulosa of the adrenal gland is the most superficial layer of the adrenal cortex, lying directly beneath the renal capsule. Its cells are ovoid and arranged in clusters or arches.
Secondary hypertension is a type of hypertension which by definition is caused by an identifiable underlying primary cause. It is much less common than the other type, called essential hypertension, affecting only 5-10% of hypertensive patients. It has many different causes including endocrine diseases, kidney diseases, and tumors. It also can be a side effect of many medications.
Hyperaldosteronism is a medical condition wherein too much aldosterone is produced by the adrenal glands, which can lead to lowered levels of potassium in the blood (hypokalemia) and increased hydrogen ion excretion (alkalosis).
An antimineralocorticoid, also known as a mineralocorticoid receptor antagonist (MCRA) or aldosterone antagonist, is a diuretic drug which antagonizes the action of aldosterone at mineralocorticoid receptors. This group of drugs is often used as adjunctive therapy, in combination with other drugs, for the management of chronic heart failure. Spironolactone, the first member of the class, is also used in the management of hyperaldosteronism and female hirsutism. Most antimineralocorticoids, including spironolactone, are steroidal spirolactones. Finerenone is a nonsteroidal antimineralocorticoid.
Liddle's syndrome, also called Liddle syndrome is a genetic disorder inherited in an autosomal dominant manner that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule, and is treated with a combination of low sodium diet and potassium-sparing diuretics. It is extremely rare, with fewer than 30 pedigrees or isolated cases having been reported worldwide as of 2008.
The captopril challenge test (CCT) is a non-invasive medical test that measures the change in renin plasma-levels in response to administration of captopril, an angiotensin converting enzyme inhibitor. It is used to assist in the diagnosis of renal artery stenosis. It is not generally considered a useful test for children, and more suitable options are available for adult cases.
Pseudohyperaldosteronism is a medical condition which mimics the effects of elevated aldosterone (hyperaldosteronism) by presenting with high blood pressure (hypertension), low blood potassium levels (hypokalemia), metabolic alkalosis, and low levels of plasma renin activity (PRA). However, unlike hyperaldosteronism, this conditions exhibits low or normal levels of aldosterone in the blood. Causes include genetic disorders, acquired conditions, metabolic disorders, and dietary imbalances including excessive consumption of licorice. Confirmatory diagnosis depends on the specific root cause and may involve blood tests, urine tests, or genetic testing; however, all forms of this condition exhibit abnormally low concentrations of both plasma renin activity (PRA) and plasma aldosterone concentration (PAC) which differentiates this group of conditions from other forms of secondary hypertension. Treatment is tailored to the specific cause and focuses on symptom control, blood pressure management, and avoidance of triggers.
Aldosterone synthase, also called steroid 18-hydroxylase, corticosterone 18-monooxygenase or P450C18, is a steroid hydroxylase cytochrome P450 enzyme involved in the biosynthesis of the mineralocorticoid aldosterone and other steroids. The enzyme catalyzes sequential hydroxylations of the steroid angular methyl group at C18 after initial 11β-hydroxylation. It is encoded by CYP11B2 gene in humans.
18-Hydroxycorticosterone is an endogenous steroid. It is a derivative of corticosterone.
The ACTH test is a medical test usually requested and interpreted by endocrinologists to assess the functioning of the adrenal glands' stress response by measuring the adrenal response to adrenocorticotropic hormone or another corticotropic agent such as tetracosactide or alsactide (Synchrodyn). ACTH is a hormone produced in the anterior pituitary gland that stimulates the adrenal glands to release cortisol, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and aldosterone.
Plasma renin activity (PRA), also known as the renin (active) assay or random plasma renin, is a measure of the activity of the plasma enzyme renin, which plays a major role in the body's regulation of blood pressure, thirst, and urine output. Measure of direct renin concentration (DRC) is technically more demanding, and hence PRA is used instead. DRC assays are still in evolution, and generally a conversion factor of PRA (ng/mL/h) to DRC (mU/L) is 8.2. A Recently developed and already commonly used automated DRC assay uses the conversion factor is 12. PRA is sometimes measured, specially in case of certain diseases which present with hypertension or hypotension. PRA is also raised in certain tumors. A PRA measurement may be compared to a plasma aldosterone concentration as an aldosterone-to-renin ratio (ARR).
Glucocorticoid remediable aldosteronism also describable as aldosterone synthase hyperactivity, is an autosomal dominant disorder in which the increase in aldosterone secretion produced by ACTH is no longer transient.
SUSPUP (serum sodium to urinary sodium to serum potassium to urinary potassium) and SUSPPUP (serum sodium to urinary sodium to (serum potassium)2 to urinary potassium) are calculated structure parameters of the renin–angiotensin-aldosterone system (RAAS). They have been developed to support screening for primary or secondary aldosteronism.
18-Hydroxy-11-deoxycorticosterone is an endogenous steroid and a mineralocorticoid. It is a hydroxylated metabolite of 11-deoxycorticosterone.
18-Hydroxycortisol is an endogenous steroid.
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