Effects of fluorocarbon blood substitute on macrophage function and host defence in mice

Delayed hypersensitivity reactions (DHR) were depressed 24 h after iv fluorocarbon emulsion (FCE) 50 ml/kg. Phagocytic % and index of peritoneal macrophage (PM) uptaking chicken red blood cells (CRBC) were markedly diminished at 6 h after iv FCE. Scanning electron micrographs of PM 24 h after FCE iv showed that the cells extensively flattened; transmission electron microscopy of PM showed that the cells contained a large number of FCE covering the organelles. Infusion of FCE 30 ml/kg significantly increased the lethality of E coli endotoxin (LPS) treated mice by tenfold, but infusion of FCE with ip hydrocortisone acetate (HCA) increased the survival of LPS-treated mice by two fold. The results indicated that FCE iv inhibited the phagocytic function of macrophage and resulted in a increased susceptibility of host to bacterial infection. Administration of ip HCA with iv FCE enhanced the host defence against infection.