Effects of hemorrhage on interleukin-1 production.

Depression of lymphocyte proliferative response occurs after trauma and hemorrhage. Because abnormalities in interleukin-1 (IL-1) production can result in depression of mitogen-induced lymphocyte proliferation, we investigated the effects of unanesthetized hemorrhage on IL-1 generation. The capacity of peripheral blood monocytes to produce IL-1 increased more than five fold by 2 h after loss of 30% of the total blood volume and returned to normal by 12 h after hemorrhage. Removal of 15% of total blood volume did not result in any alterations in IL-1 production. These results show that the diminished lymphocyte proliferative response which occurs after unanesthetized hemorrhage was not due to decreased IL-1 production. The increase in IL-1 generation which occurs shortly after severe hemorrhage may play a role in mediating the acute phase reaction which follows hemorrhage and trauma.