Identification of an Adrenomedullin precursor fragment in plasma of sepsis patients.

Adrenomedullin and PAMP are potent vasodilatory peptides derived from a common larger precursor peptide. Elevation of circulating levels of both peptides has been described for diseases involving dysfunction of the cardiovascular system. However, the reliable quantification has been hampered by their short half-life times and - as known for Adrenomedullin -- the existence of a binding protein. Here we report the identification of another peptide derived from the Adrenomedullin precursor, termed proADM 45-92, which is present in large concentrations in plasma of septic shock patients. This peptide is produced in stoichiometric amounts to Adrenomedullin and PAMP, but -- contrary to them -- is apparently non-functional and stable. Thus, proADM 45-92 represents a suitable diagnostic target which could be used to assess the concentrations of Adrenomedullin gene products released into the bloodstream.