Effect of endotoxin on mouse serum angiotensin-converting enzyme

The effect of endotoxin on serum levels of angiotensin-converting enzyme (ACE) in mice was studied. At a dose of 0.5 mg/kg intraperitoneally administered, endotoxin from Escherichia coli and Serratia marcescens lowered serum ACE. The effect of E. coli endotoxin on serum ACE can be demonstrated by 2 h, it returns to control values in 24 h, and is not dose-dependent in the 0.5 to 8.0 mg/kg range. The reduction of mouse serum ACE by parenteral endotoxin mimics the lower serum ACE observed in patients with gram-negative sepsis.