A role for adrenomedullin in the pathogenesis of alveolar edema
© BioMed Central Ltd 2006
Published: 4 August 2006
Christ-Crain and colleagues  established in their work a close relationship between pro-adrenomedullin levels and severity of community acquired pneumonia. This raises the question of whether this peptide or its precursor adrenomedullin are involved in the pathogenesis of the respiratory compromise in pneumonia. Adrenomedullin induces nitric oxide (NO) production in endothelial cells through an increase in intracellular calcium levels, which activates NO synthetase . NO has been linked to endotoxin induced acute lung injury in which the NO scavenger N-acetyl cysteine reduced exhaled NO levels and lung water . The mechanism by which NO reduces alveolar fluid clearance and contributes to the extent of pulmonary fluid accumulation in lung injury has been clarified: NO reduces both the activity of apical alveolar epithelial sodium channels and the baso-lateral alveolar epithelial sodium-potassium ATPase, which regulate alveolar sodium and water absorption. Sodium absorption hereby generates the osmotic gradient, drawing alveolar fluid through alveolar epithelial aquaporin channels and paracellular pathways [4, 5].
Future research needs to investigate the role of adrenomedullin in the generation of pulmonary NO production in lung injury and whether treatments leading to a reduction of adrenomedullin levels can reduce the severity and extent of alveolar edema in pneumonia and septicemia.
- Christ-Crain M, Morgenthaler NG, Stolz D, Mueller C, Bingisser R, Harbarth S, Tamm M, Struck J, Bergmann A, Mueller B: Pro-adrenomedullin to predict severity and outcome in community-acquired pneumonia [ISRCTN04176397]. Crit Care 2006, 10: R96. 10.1186/cc4443PubMed CentralView ArticlePubMed
- Hirata Y, Hayakawa H, Suzuki Y, Suzuki E, Ikenouchi H, Kohmoto O, Kimura K, Kitamura K, Eto T, Kangawa K, Matsuo H, Omata M: Mechanisms of adrenomedullin-induced vasodilation in the rat kidney. Hypertension 1995, 25: 790-795.View ArticlePubMed
- Kao SJ, Wang D, Lin HI, Chen HI: N-acetylcysteine abrogates acute lung injury induced by endotoxin. Clin Exp Pharmacol Physiol 2006, 33: 33-40. 10.1111/j.1440-1681.2006.04320.xView ArticlePubMed
- Guo Y, DuVall MD, Crow JP, Matalon S: Nitric oxide inhibits Na+ absorption across cultured alveolar type II monolayers. Am J Physiol 1998, 274: L369-L377.PubMed
- Eisenhut M: Changes in ion transport in inflammatory disease. J Inflamm (Lond) 2006, 3: 5.View Article