Sex difference and the influence of endotoxin and hypertransfusion in spleen colony formation.

Lethally whole-body irradiated mice upon receiving a relatively small quanity of marrow cells show a distinct sex difference in ability to support colony formation in spleen and cell proliferation in femoral marrow. The difference should be defined with reference to the organ in question. Female mice manifest more efficient splenic haematopoiesis while among the males myeloid haematopoiesis, as measured by 59Fe and 125IUdR incorporation, seems to be greater. Endotoxin treatment and hypertransfusion exert profound influences, interacting with the sex-hormonal status of the animal.