What is captopril Renography?

A captopril renal scan is used to evaluate for the presence of renal artery stenosis and renovascular hypertension. This captopril scan is performed in order to rule out renal artery stenosis in patients with high blood pressure.

What is a renin provocation test?

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.

How does captopril challenge test work?

The principle the captopril test is based is the suppression of the serum concentration of aldosterone and an increase in the level of PRA when angiotensin-converting enzyme is inhibited in patients without autonomous aldosterone secretion [1].

Why ACE inhibitors are contraindicated in bilateral renal artery stenosis?

Angiotensin-converting enzyme inhibitors (ACEIs) are contraindicated in patients with bilateral renal artery stenosis due to risk of azotemia resulting from preferential efferent arteriolar vasodilation in the renal glomerulus due to inhibition of angiotensin II.

What is renovascular hypertension?

Renovascular hypertension is high blood pressure due to narrowing of the arteries that carry blood to the kidneys. This condition is also called renal artery stenosis.

What does ACE enzyme do?

Angiotensin-converting enzyme (ACE) inhibitors work by primarily relaxing the blood vessels and thereby bringing down the elevated blood pressure. They are a class of medicines that are used to treat high blood pressure, heart problems, and other conditions.

What does a high Aldo PRA ratio mean?

High levels of aldosterone can result from a condition called primary aldosteronism (PA), which causes high blood pressure. PA is also known as hyperaldosteronism or Conn syndrome. It can lead to a variety of other health conditions. A high level of aldosterone typically causes a dip in renin level.

Is aldosteronism a primary?

Primary aldosteronism (al-DOS-tuh-ro-niz-um) is a hormonal disorder that leads to high blood pressure. It occurs when your adrenal glands produce too much of a hormone called aldosterone. Your adrenal glands produce a number of essential hormones, including aldosterone.

Why does ACE inhibitor increase creatinine?

—Felix N. Starting an ACE inhibitor can result in small and nonprogressive serum creatinine increases that reflect decreased glomerular filtration rate and reduced intraglomerular pressure.

How did the discovery of ACE inhibitors lead to their development?

Discovery and development of ACE inhibitors. The discovery of an orally inactive peptide from snake venom established the important role of angiotensin converting enzyme (ACE) inhibitors in regulating blood pressure. This led to the development of Captopril, the first ACE inhibitor.

What is the role of Ace in the renin–angiotensin system?

Anatomical diagram of the renin–angiotensin system, showing the role of ACE at the lungs. ACE hydrolyzes peptides by the removal of a dipeptide from the C-terminus. Likewise it converts the inactive decapeptide angiotensin I to the octapeptide angiotensin II by removing the dipeptide His-Leu.

What are aceace inhibitors and how do they work?

ACE inhibitors have also been shown to cause a central enhancement of parasympathetic nervous system activity in healthy volunteers and patients with heart failure.

What are the possible complications of ACE inhibitors?

Hyperkalemia (high concentration of potassium in the blood) is another possible complication of treatment with an ACE inhibitor due to its effect on aldosterone. Suppression of angiotensin II leads to a decrease in aldosterone levels.