Effect of steroids during Escherichia coli endotoxinaemia in rabbits

A study was carried out on the effect of high doses of methylprednisolone to rabbits in combination with or after challenging them with Escherichia coli endotoxin. The animals given steroids simultaneously with the endotoxin or 2-6 h thereafter all had significantly higher white cell counts 24 h after endotoxin infusion. A second dose of endotoxin given 24 h after the first caused a rapid fall in white cell count, and no difference between the groups could then be observed 2 h later. The most striking effect was observed when methylprednisolone was administered simultaneously with the endotoxin. This caused a suppression of the clearance of endotoxin from the circulation, and this in turn could probably account for some newly synthesized thromboplastin expressed by the circulating monocytes. Furthermore, monocyte activation appears to be significantly higher in the animals receiving steroids than in the controls when the animals are subjected to two doses of endotoxin injections 24 h apart. Thus, high doses of methylprednisolone cannot be seen to have any beneficial effect as judged from the parameters tested in the present study.