Renin Angiotensin Aldosterone System (RAAS)

-


Renin-Angiotensin Aldosterone System

It is a hormone system involved in the regulation of blood pressure comprising of renin, aldosterone and angiotensin II 1.It is also a determinant of renal failure as it controls the balance of electrolytes in the body through coordinated on the kidneys, blood vessels as well as heart.


Renin Release

Renin is released from juxtaglomerular apparatus due to a number of factors;

  • Macula densa cells detect reduced delivery of sodium to the distal convoluted tubule.
  • Baroreceptors in the afferent arterioles detect reduced perfusion pressure.
  • Beta 1-adenoreceptors detects sympathetic stimulation of juxtaglomerular apparatus.


Production of Angiotensin II

Angiotensinogen is a protein cleaved by renin to angiotensin I which in turn gets converted to angiotensin II by angiotensin-converting enzyme (ACE), this takes place in liver 2.

  • Angiotensin II is a vasoconstrictor and binds to G-protein coupled receptors, AT1 and AT2.
  • Renal failure leads to an increase in the production of angiotensin II and thus vasoconstriction of renal vessels leads to hypertension 3 thus increasing workload on the heart and leads to heart failure 4.



Clinical Relevance

ACE inhibitors inhibit the action of angiotensin-converting enzyme thus reducing the levels of angiotensin II in the body consequently reducing the activity of RAAS. Therefore the physiological effects are;

  • Decreased cardiac output.
  • Decreased arteriolar vasoconstriction.
  • Reduced excretion of potassium from the kidneys.


By: ZOHA KHAN


References

  1. Atlas, S. A. The renin-angiotensin aldosterone system: pathophysiological role and pharmacologic inhibition. J. Manag. care Pharm. 13, 9–20 (2007).
  2. Re, R. N. Mechanisms of disease: local renin–angiotensin–aldosterone systems and the pathogenesis and treatment of cardiovascular disease. Nat. Clin. Pract. Cardiovasc. Med. 1, 42–47 (2004).
  3. Onuigbo, M. A. C. & Onuigbo, N. T. C. Worsening renal failure in older chronic kidney disease patients with renal artery stenosis concurrently on renin angiotensin aldosterone system blockade: a prospective 50-month Mayo-Health-System clinic analysis. QJM An Int. J. Med. 101, 519–527 (2008).
  4. Dzau, V. J. Tissue renin-angiotensin system: physiologic and pharmacologic implications. (American Heart Association, 1988).

Comments

Post a Comment

Popular posts from this blog

Hydrogels

-
Image
By: Batool Murtaza Abstract Hydrogels have been around for almost half a century, and one of the oldest recordings of crosslinked hydroxyethyl methacrylate (HEMA) hydrogels dates back to the 1950s. Hydrogels continue to intrigue material scientists and biological researchers today, and significant progress has been made in terms of formulations and applications. Hydrogels are a type of material that consists of a self-supporting, water-swollen three-dimensional (3D) viscoelastic network that allows molecules and cells to diffuse and adhere. Hydrogels, on the other hand, have recently received a lot of attention for their usage in a wide range of biological applications, including cell therapies, wound healing, cartilage/bone regeneration, and medication sustained release. This is due to their biocompatibility and physical qualities that are similar to those of natural tissue. Based on ancient and new papers in this subject, this study attempts to provide an overview ...
Read more

Innovations in Vaccinology: The Rise of Recombinant Genetic Shields

-
Image
Immune protection against infectious diseases is a crucial objective in both human and animal health. Currently, the focus of the vaccine landscape is primarily on COVID-19, which has required an unprecedented global effort to develop and deploy vaccines rapidly. Consequently, vaccination has become a dominant subject in scientific literature, and detailed discussions on specific immunization strategies and vaccine-induced immune responses are widespread in the media. This situation has underscored the challenges posed by emerging viral pandemics and the need for a universal approach to vaccine development, regardless of the pathogen-host combination. Traditional vaccine formulations, such as inactivated or attenuated versions of the whole infectious agent, have faced limitations, such as potential safety risks associated with chemical inactivation or the risk of reverting to virulence with attenuated strains. As a result, there is a growing interest in recombinant subunit vaccines. ...
Read more

Registration Form for Volunteer Batch 2k22

-
Image
Here are some important instructions for volunteership program This is one unique kind of volunteership program, most activities will be followed with the SOPs and the whole activities will be designed and conducted by the SBA team so therefore, you have to establish the following procedure to get selected. All the individuals from life sciences background are encouraged to apply for this volunteership program and be a part of our team.!! ✨Grab this amazing opportunity to: Enhance your skills Know your potential Learn new and exciting things beyond convention Be a part of the scientific team You all are welcome to apply via the online portal on our page. Please fill in the online registration form and make sure it is very clear and concise.     Issue Date:    22-October-2022  Deadline:      27-October-2022 Link:   https://forms.gle/T4k4iFHoPQejZjny6   Phase-I: Forms should be filled with proper information and clear obje...
Read more