Chemical Identity

Property	Value
Chemical Formula	C50H71N13O12
Molecular Weight	1046 Da
CAS Number	4474-91-3
Peptide Class	Octapeptide Hormone
Sequence	DRVYIHPF
Receptor	AT1, AT2

Structure

Angiotensin II (Ang II) is an octapeptide produced from angiotensinogen through sequential cleavage by renin (to Ang I) and angiotensin-converting enzyme (ACE) (to Ang II). The His6-Pro7 bond is essential for receptor binding. Ang II is the primary effector of the renin-angiotensin-aldosterone system (RAAS).

Mechanism of Action

Ang II binds AT1 receptors (vasoconstriction, aldosterone, inflammation, fibrosis) and AT2 receptors (vasodilation, anti-proliferation). AT1 activation causes potent vasoconstriction, sodium and water retention (via aldosterone), sympathetic nervous system activation, cardiac hypertrophy, and vascular remodeling.

Clinical Applications

• Blood pressure regulation: Primary endogenous vasopressor
• Angiotensin II (Giapreza): Synthetic Ang II for distributive shock
• RAAS blockers: ACE inhibitors, ARBs target Ang II signaling
• Heart failure: RAAS activation in disease progression
• Kidney disease: Ang II-mediated glomerular hypertension

Pharmacology

• Half-life: 1-2 minutes (circulating), effects sustained by local production
• Potency: 40x more potent than Ang I as vasoconstrictor
• Production: ACE in lungs (primary), local tissue ACE
• Degradation: Aminopeptidases (to Ang III), ACE2 (to Ang 1-7)

References

• Skeggs, L.T., et al. (1956). The amino acid sequence of hypertensin II. Journal of Experimental Medicine, 104, 193-197.
• Khanna, A., et al. (2017). Angiotensin II for distributive shock (ATHOS-3). New England Journal of Medicine, 377, 419-430.