The Reduction of Endotoxin-induced Loss of Protein into the Extra-cellular Space: Evidence for its Benefit in Shock?

Abstract

Intravenous injection of endotoxin (E. coli lipopolysaccharide, 0127:B5) 3-30 mg/kg brought about a dose-dependent decrease in protein levels in rat plasma. The decrease was however not accompanied by corresponding decrease in haematocrit. The packed cell volume was found to rise with the dose of endotoxin lipopolysaccharide given. Dexamethasone alone (20 ingikg) did not affect the protein level, but when it was administered 20 minutes before the injection of 10 mg/kg lipopolysaccharide, it significantly prevented the reduction of protein levels by endotoxin (p<0.05). Interestingly, dexamethasone also prevented the rise of haematocrit induced by lipopolysaccharide. The dexamethasone prevention of the increase brought about by lipopolysaccharide indicates that dexamethasone relies on its effect in preventing leakage of protein material from the vasculature to the extracellular space. This appears to be the basis of its beneficial effect in shock, edema and inflammatory conditions.