Ultrastructure and functional state of rabbit lymphoid cells after repeated exposure to lipopolysaccharide and external heating.

The ultrastructure and proliferative activity of lymphoid tissue cells in rabbits after repeated exposures to lipopolysaccharide (LPS) or external heating were studied. It was shown that in conditions of the same increase in body temperature the production of IL-1-like activity by blood and splenic cells was inhibited to the same extent in both groups of animals. It was suggested that one of the causes of LPS-induced tolerance may be events provoked by temperature factor per se. There were similar changes in activity of epithelial cells in the thymus, reticular cells in the spleen, in activation of mast cells in these organs and in proliferative processes in the thymus after both exposures, however inhibition of proliferative activity of splenic and lymph node cells was observed only in LPS-treated animals.