Effect of Leukocyte-Promoting Factor (LPF) on Survival of X-Irradiated Mice.

Abstract
Treatment of irradiated mice with leukocytosis-promoting factor did not increase their 30-day survival. This fact strongly suggests that if survival of irradiated mice into which normal spleens have been implanted is due to a "humoral" factor released by the spleen, such a factor is unrelated to the specific leukocyte-promoting factor obtained from sterile exudates. LPF, a logical therapeutic agent, is ineffective in reducing X-ray mortality in mice.