Chemical Identity

Property	Value
Chemical Formula	C252H396N78O72S2
Molecular Weight	5729 Da
Peptide Class	Vasodilator Peptide (52 amino acids)
Disulfide Bonds	1 (Cys16-Cys21, 6-membered ring)
Receptor	CLR/RAMP2 (AM1), CLR/RAMP3 (AM2)

Structure

Adrenomedullin (ADM) is a 52-amino acid vasodilatory peptide with a single intramolecular disulfide bond forming a 6-membered ring in the N-terminal region and a C-terminal amidation. It belongs to the calcitonin gene-related peptide (CGRP) family and shares structural homology with amylin and CGRP.

Mechanism of Action

ADM binds calcitonin receptor-like receptor (CLR) with RAMP2 (AM1 receptor) or RAMP3 (AM2 receptor), activating adenylyl cyclase and increasing cAMP. This causes potent vasodilation, natriuresis, inhibition of aldosterone, and cardioprotective effects including anti-fibrotic and anti-apoptotic actions.

Clinical Applications

• Heart failure: Elevated levels as compensatory mechanism
• Pulmonary hypertension: Vasodilatory and anti-remodeling effects
• Sepsis: Elevated levels correlate with severity
• Pre-eclampsia: Altered ADM levels in pregnancy complications
• Cancer: ADM promotes tumor angiogenesis

Pharmacology

• Half-life: 22 minutes (plasma)
• Potency: 10x more potent than CGRP as vasodilator
• Distribution: Adrenal medulla, heart, vasculature, brain
• Receptor: CLR/RAMP complexes (shared with CGRP and amylin)

References

• Kitamura, K., et al. (1993). Adrenomedullin: a novel hypotensive peptide. Biochemical and Biophysical Research Communications, 192, 553-560.
• Nishikimi, T., et al. (2006). Adrenomedullin in cardiovascular disease. Cardiovascular Research, 71, 210-220.