Renin-angiotensin system is a hormone system involved in the regulation of arterial blood pressure and plasma sodium concentration.
When renin is liberated in the blood, it acts on angiotensinogen (a circulating layer) which goes through proteolytic cleavage to make decapeptide angiotensin I. Vascular endothelium has an enzyme called angiotensin transforming enzyme that separates two amino acids and form angiotensin II (AII) and other tissues in the body including brain and heart also form angiotensin II (AII) .
Different important functions of Renin-angiotensin system are mentioned below:
- Build resistance vessels hence increasing arterial pressure and systemic vascular resistance.
- Stimulates delivery of sodium at different renal tubular sites and increasing the body’s water retention.
- Stimulates the liberation of vasopressin from posterior pituitary and increases liquid retention by the kidneys.
- Provides release of norepinephrine from sympathetic nerves and prevents norepinephrine uptake thereby optimizing sympathetic adrenergic function.
- Stimulates vascular hypertrophy and cardiac hypertrophy.
- The renin-angiotensin route is not regulated only by the mechanisms which encourage the release of renin but also regulate by natriuretic peptides that are released by the human heart and these peptides serve as a critical counter regulating the system.
Manipulative therapies play a major role in treating heart failure and hypertension. Every receptor blockers and ACE inhibitors are utilized in decreasing arterial pressure, blood volume, ventricular afterload, and ventricular preload along with vascular hypertrophy and reverse cardiac.
Therapeutic approaches that aim towards a complete inhibition of RAAS offers more clinical benefits for patients with renal and cardiovascular disorders. These approaches can involve dual blockade by using the combination of ARBs and ACE I or therapeutic modalities like direct renin inhibition with aliskiren which is a recently approved treatment of hypertension.
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