Fluids, Electrolytes & Nutrition: Renin-Angiotensin-Aldosterone System (RAAS)

Renin-Angiotensin-Aldosterone System (RAAS)

Renin

  • Stimulation: Decreased Renal Perfusion (Hypotension)
  • Secretion: Kidney/Juxtaglomerular Apparatus of Afferent Arterioles
    • Also Secreted by Macula Densa from Hypernatremia
  • Effect: Converts Angiotensinogen (Secreted in the Liver) to Angiotensin I

Angiotensin Converting Enzyme (ACE)

  • Secretion: Lungs (Primarily)
    • Other Sites of Secretion: Renal Endothelium & Brain
  • Effect: Converts Angiotensin I to Angiotensin II

Angiotensin II

  • Converted from Angiotensin I by Angiotensin Converting Enzyme (ACE)
  • Effects:
    • ADH/Vasopressin Production (CNS)
    • Vasoconstriction
    • Aldosterone Secretion (Adrenal Cortex)
    • Sodium Reabsorption & Hydrogen Excretion (Na/H Exchanger in Proximal Tubules)

Aldosterone