Angiotensinogen is an acute-phase protein in man.

Accumulating information concerning the structure of angiotensinogen suggests a resemblance of this component of the renin-angiotensin system to the acute-phase protein alpha 1-antitrypsin. Compared to a group of age- and sex-matched controls without signs of infection, markedly elevated levels of angiotensinogen (increase in median value: 70%), alpha 1-antitrypsin (102%), caeruloplasmin (76%), haptoglobin (261%), and orosomucoid (162%) were found in plasma from 14 patients with acute inflammatory disease. This finding indicates that angiotensinogen should be included in the list of acute-phase proteins in man, and raises the question whether angiotensinogen is involved in the regulation of the renin-angiotensin system during inflammation and tissue injury.