Early Fall of Circulating Iron and Rapid Rise of Lactoferrin in Septicemia and Endotoxemia: An Early Defence Mechanism

Abstract

Total serum iron, plasma lactoferrin and circulating leukocytes were measured in piglets during the early phase of severe gram-negative septicemia and endotoxemia in 3 experimental settings: intravenous (i.v.) infusion of lipopolysaccharide (LPS) (n = 8), i.v. infusion of live Escherichia coli (n = 7) and intraperitoneal (i.p.) infusion of E. coli (n = 6). Iron dropped significantly during the first 30 min of LPS infusion from a median of 32 μM to 13.4 μM. A similar decrease in serum iron was demonstrated in the 2 other groups with minimum values at 120 min after the start of E. coli infusion. Plasma levels of lactoferrin increased significantly 120 min after the start of LPS infusion (median 6 mg/l) when compared to preinfusion values (0.25 mg/l). After i.v. infusion of E. coli a significant rise of plasma lactoferrin was demonstrated already 30 min after bacterial infusion (to 2.1 mg/l) compared to preseptic values (0.8 mg/l). This increase was accompanied with a significant drop of circulating leukocytes (to 7.3±10⁹/l) compared to before the infusion (17±10⁹/l) in the pigs given E. coli i.v. After i.p. E. coli infusion no significant change of plasma lactoferrin was observed. The rapid fall of total serum iron seen during endotoxemia and E. coli septicemia may in part be explained by the release of lactoferrin from granulocytes and the clearance of iron-bound lactoferrin in the blood or peritoneal cavity.