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Angiotensin I and II in the blood
Medical expert of the article
Last reviewed: 23.04.2024
The reference concentration (norm) of angiotensin I in blood plasma is less than 25 pg / ml; angiotensin II - 10-60 pg / ml.
Renin, which enters the blood from the juxtaglomerular apparatus of the kidneys, cleaves the angiotensinogen decapeptide angiotensin I, which, in turn, under the influence of the ACE, two amino acids are cleaved and angiotensin II is formed. Angiotensin II has two main functions: it stimulates the synthesis and secretion of aldosterone in the adrenal cortex and causes a reduction in peripheral blood vessels. His pressor action is 30 times higher than that of norepinephrine. In the kidneys, angiotensin II, narrowing the vessels, causes a decrease in blood flow and, as a consequence, a decrease in glomerular filtration. The action of angiotensin II for a short time (several minutes), as it quickly degrades in the blood under the influence of peptidase (angiotensinase) on inactive fragments.
The study of the concentration of angiotensin I and II in blood plasma is conducted to identify the involvement of the renin-angiotensin-aldosterone system in the pathogenesis of arterial hypertension, chronic heart failure, edematous syndrome.
Diseases and conditions in which the activity of angiotensin in the blood plasma can change
Angiotensin I decreased
- Cohn's syndrome (primary hyperaldosteronism)
- Dehydration
- After kidney removal
Angiotensin I elevated
- Increased blood pressure (renal hypertension)
- Tumors of the juxtaglomerular renal apparatus secreting renin
- Kidney cancer with hyperreneinemia
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