The effect of endotoxin on peripheral blood lymphocytes in the rat

We have studied the effects on peripheral blood lymphocytes of the administration to rats of a single dose of endotoxin. Lymphopenia occurred during the first hour, and persisted during 24 hours. Lymphocyte subpopulations were examined by flow cytometry. T-lymphocytes were relatively resistant to the initial effects of endotoxin, but there were no differences in the responses of cells identified as T-helper or T-suppressor/cytotoxic lymphocytes. The effects of endotoxin on peripheral blood lymphocytes is less extreme but appears more persistent than the effects on granulocytes.