Angiotensin II

Where it comes from

Made in

Formed in blood and in tissues when ACE cuts angiotensin I

Sent out by

Follows renin: low pressure, low salt, blood loss, sympathetic activity

Acts on

• Arterioles
• Adrenal cortex (aldosterone)
• Kidney (sodium reabsorption, efferent arteriole)
• Hypothalamus (thirst, vasopressin)
• Heart and vessels (growth)

What it does

• Raises blood pressure within seconds
• Makes the adrenal release aldosterone and the kidney hold sodium
• Drives thirst and salt appetite
• Thickens heart and vessel walls and scars the kidney when chronically high ³

In medicine

• ACE inhibitors and angiotensin receptor blockers are among the most prescribed medicines in the world, for hypertension, heart failure and kidney disease; there are too many to list, and they all end in -pril or -sartan
• Synthetic angiotensin II has been approved since 2017 as an infusion to raise blood pressure in septic and other distributive shock ¹²
• Lasts under a minute in blood, which is why it is an infusion and never a tablet

Beyond the body’s own use

• The approved infusion rests on a 344-patient trial in which it lifted mean arterial pressure in 69.9% of patients against 23.4% on placebo. The trial was not powered for survival, and death by day 28 did not differ ¹
• It is studied in cognition, fibrosis and cancer, almost always by blocking it rather than by giving it; none of those uses is approved ³
• Nothing circulates outside medicine. An eight-residue peptide with a half-life under a minute is useless as anything but a controlled infusion, and the hospital preparation is a prescription medicine ²