Key developments in renin-angiotensin-aldosterone system inhibition

Area of Science:

• Cardiovascular Science
• Nephrology
• Endocrinology

Background:

• The Renin-Angiotensin-Aldosterone System (RAAS) was initially considered simple.
• Development of RAAS blockers (renin inhibitors, ACE inhibitors, AT(1)-receptor blockers, MRAs) revealed complexity.
• New RAAS components and pathways impact drug efficacy and adverse effects.

Purpose of the Study:

• To explore newly identified RAAS components and pathways.
• To understand their contribution to RAAS blocker effectiveness and side effects.
• To elucidate the role of Angiotensin II in distal nephron sodium and potassium handling.

Main Methods:

• Review of existing literature on RAAS blockers and their effects.
• Analysis of identified RAAS components and their interactions.
• Investigation of Angiotensin II's role in renal ion transport.

Main Results:

• Increased renin during blockade may activate the prorenin receptor (PRR), potentially causing harm.
• Increased Angiotensin II during AT(1)-receptor blockade may stimulate beneficial AT(2) receptors.
• Elevated Angiotensin 1-7 activates Mas receptors, promoting cardioprotective, renoprotective, and stem cell repair effects.
• Angiotensin II plays a role in distal nephron sodium and potassium handling.

Conclusions:

• The RAAS is more complex than previously understood.
• New pathways involving PRR, AT(2) receptors, and Angiotensin 1-7/Mas receptor axis modulate RAAS inhibitor actions.
• Understanding these pathways is crucial for optimizing RAAS-targeted therapies and managing electrolyte balance.