Tumour necrosis factor mediates bacterial translocation after haemorrhagic shock and endotoxaemia

Abstract

Objective: To assess the extent of bacterial translocation after haemorrhagic shock and reperfusion, and the involvement of tumour necrosis factor (TNF) in its mediation. Design: Controlled, randomised prospective experiment. Subjects: 87 rats in 7 groups. Interventions: Haemorrhagic shock was induced in rats for 1 hour. Endotoxaemia was induced in a second group by the injection of lipopolysaccharide: A third group was injected with exogenous TNF. Some of the animals were further treated with anti-TNF. Measurements: After 24 hours, bacterial translocation in blood and in several remote organs, and serum TNF concentrations were measured. Results: High bacterial counts were found in all remote organs of rats with haemorrhagic shock or endotoxaemia. Their serum TNF concentrations were significantly higher than in the corresponding sham-operated controls. Anti-TNF significantly reduced the extent of bacterial translocation. Rats, the only treatment of which was exogenous TNF, developed substantial bacterial translocation. Conclusion: Bacterial translocation is associated with increased serum TNF, and can be minimised by anti-TNF. This, and the triggering of translocation in unprovoked animals by TNF alone, suggest that TNF may be the stimulator, and not the consequence, of bacterial translocation.