Variation in toxicity of Escherichia coli endotoxin after treatment with perfluorated blood substitutes in mice.

Treatment with perfluorochemicals (PFCs) shows a temporary decrease in phagocytic activity as measured by carbon clearance. The importance of this effect was checked by investigating the lethality after administrations of PFCs and Escherichia coli endotoxin in mice (NMRI strain). When endotoxin was applied simultaneously with PFC (4.4 g/kg body weight, a dose which could compensate a loss of a third of blood volume) the lethality rose 7.8-fold. If the challenge with endotoxin occurred later than 12 h after PFC injection, the increase of lethality was of a distinctly smaller degree. By means of pretreatment with various substances the increased lethality of endotoxin could be shifted in the direction of the control. C 48/80, aristolochic acid, and hydrocortisone were effective in this respect; zymosan remained ineffective. The results show a weakened resistance towards toxins from the intestinal tract under PFC administration; precaution in this regard should be taken during therapy with PFC.