ADM

ADM Full Name

adrenomedullin

ADM Introduction

Adrenomedullin (ADM) is a highly conserved, 52-amino acid bioactive peptide hormone belonging to the calcitonin gene-related peptide (CGRP) superfamily. Originally isolated from human pheochromocytoma tissue in 1993, ADM is now recognized to be widely synthesized and secreted by a diverse array of cell types, most notably vascular endothelial cells, vascular smooth muscle cells, and macrophages. Mechanistically, ADM exerts its pleiotropic biological effects by binding to a highly specialized heterodimeric receptor complex. This complex is composed of the calcitonin receptor-like receptor (CRLR) coupled with specific receptor activity-modifying proteins (RAMPs, primarily RAMP2 and RAMP3), which together govern the receptor's specificity and intracellular signaling cascades.

Figure 1. Summary diagram of the proposed adrenomedullin (ADM) signaling pathway in the retina. (Source: Blom J, et al. 2012)

The hallmark physiological role of ADM is acting as a potent, long-lasting endogenous vasodilator. By directly relaxing vascular smooth muscle and simultaneously stimulating the production of nitric oxide (NO) in endothelial cells, ADM tightly regulates vascular tone, systemic blood pressure, and local tissue perfusion. Beyond its profound hemodynamic functions, ADM plays an indispensable role in maintaining endothelial barrier integrity and regulating developmental angiogenesis. Furthermore, it acts as an intrinsic survival factor; during episodes of severe oxidative stress, ischemia, or tissue hypoxia, locally secreted ADM exerts pronounced anti-apoptotic and anti-inflammatory tissue-protective effects to prevent catastrophic cellular damage.

Clinically, the systemic dysregulation of ADM is deeply intertwined with life-threatening cardiovascular and infectious diseases. In the context of critical care medicine, ADM has emerged as a paramount, independent prognostic biomarker for sepsis and septic shock. During severe systemic infections, widespread endothelial damage and massive inflammatory cytokine storms trigger an extreme compensatory overexpression of ADM. Consequently, highly elevated circulating levels of bioactive ADM (bio-ADM) strongly correlate with the severity of vasoplegia (refractory hypotension), capillary leakage, and subsequent multi-organ failure. Routinely measuring bio-ADM allows clinicians to accurately predict mortality risk and strategically triage critically ill septic patients. Furthermore, in the field of oncology, ADM frequently acts as a pathological driver within the tumor microenvironment. Highly aggressive malignancies, such as pancreatic adenocarcinoma and triple-negative breast cancer, actively upregulate ADM to fuel tumor neovascularization, inhibit immune cell infiltration, and promote distant metastasis, making the ADM signaling axis a highly compelling target for novel anti-angiogenic cancer therapies.

Alternate Names for ADM

ADM; adrenomedullin; AM; PAMP

• 1. Blom J, et al. Evidence for a functional adrenomedullin signaling pathway in the mouse retina. Mol Vis. 2012;18:1339-53. Epub 2012 May 30.
  2. Lundberg OHM, et al. Bioactive adrenomedullin in sepsis patients in the emergency department is associated with mortality, organ failure and admission to intensive care. PLoS One. 2022 Apr 28;17(4):e0267497.