Bone marrow granulopoietic response to scalds and wound infection in mice.

Phagocytic cell function is often suppressed after thermal injury. It has been suggested that one of the mechanisms of suppression is a direct effect of thermal injury upon these cells. In the present study we examined whether bone marrow haemopoietic stem cells were suppressed by thermal injury similar to the effect seen on mature haemopoietic cells. Results of both in vitro bone marrow cell cultures and in vivo spleen colony assays showed that granulopoiesis was not suppressed but activated early on day 3 following scald injury or scald plus wound infection in mice. In the latter group, stimulation of granulopoiesis persisted throughout the entire observation period of 9 days. These studies indicate that bone marrow pluripotent stem cells are capable of modulating their direction of differentiation according to body demand and deviate toward the granulocyte series following thermal injury.