Abstract: Objective The ability of recombinant murine interleukin-12 (rmIL-12) to facilitate recovery of bone marrow hematopoietic stem cells (HSC) from irradiation in mice model were evaluated. Method The rmIL-12 treated SPF BALB/c mice or bone marrow hematopoietic stem cells obtained from the animals before and after irradiation were examined for the viable counts and apoptosis of bone marrow hematopoietic stem cells. Results The rmIL-12 treatment before and after irradiation was effective to increase hematopoietic stem cells of suppressed bone marrow and reduce apoptosis both in obtained hematopoietic stem cells and in mice. Conclusion The rmIL-12 had obvious effect on recovery of hematopoietic stem cells from irradiation induced damage. Moreover, this study provided experimental evidence for IL-12 as clinic therapy to treat diseases associated with hematopoietic cytopenia.

Key words: rmIL-12, Mice, Bone Marrow, Hematopoietic Stem Cell, Irradiation, Stem Cell Counts, Apoptosis