Objective To investigate the effects of ectomesenchymalstem cells on hematopoiesis after total body irradiation in rats. Methods The primary ectomesenchymal stem cells were isolated from E11.5 SD fetal mandibular processes by 25g/L trypsin and cultured with DMEM/F12. The morphology and growthrate were observed by inverted microscope. Eighty SD male rats randomly dividedinto ectomesenchymal stem cells group (n=20), fibroblast group(n=20), saline group(n=20) and control group(n=20), the first three groups were irradiated with 60Co γ rays at 6.0 Gy. The number of their bone marrow nucleated cells was counted after 4 weeks; the forming ability of colony-forming unit-granulocyte macrophage(CFU-GM) and histopathology of bone marrow were also observed. Results The cultured cells displayed monolayer growth and fibroblast-like with 2-4 processes. The ectomesenchymal stem cells could increase the number of bone marrow nucleated cells and peripheral blood white cell count, and improve the forming ability of CFU-GM. After 4 weeks of transplantation, the number of the peripheral blood white cells in group A was more than that in groups B and C(Plt;0.05), the contents of Hb in groups A and D was significantly higher than those in groups B and C(Plt;0.0). After 4 weeks, the bone morrow nucleated cells in group A were significant more than those in groups B and C(Plt;001); CFU-GM in groups A and D was higher than that in groups B and C(Plt;0.01). Conclusion Ectomesenchymal stem cells have characteristics of stem cells. It may improve hematopoiesis recovery of irradiated rats.
Objective To explore composition of volatile organic compounds (VOCs) in exhaled breath of low-dose radiation-damaged Sprague-Dawely (SD) rats by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS), and search for the differential metabolites of VOCs in the series of rats after radiation damage, and establish a noninvasive radiation damage detection method. Methods SD rats were randomly divided into five groups (a blank group, a 0.5-Gy group, a 1-Gy group, a 2-Gy group, and a 3-Gy group), with 8 rats in each group. A low-dose radiation injury model was established in rats. After the cobalt source radiation damage was performed, the body weight of rats was recorded, peripheral blood hematology was analyzed, and the exhaled breath of rats was collected on the 1st, 5th, 9th and 13th day. The composition of VOCs in the exhaled breath was analyzed by using the TD30-GC-MS technique, and multivariate statistical analyses were carried out to explore and obtain the differentiated metabolites after the radiation damage. Results After radiation damage, the rats showed a short-term decrease in body weight, peripheral blood and lung tissue sections were different, and the content of VOCs components in the exhaled breath of the damaged rats was significantly different from that of the rats in the blank group. Among them, four VOCs, acetophenone, nonanal, decanal and tetradecane increased, while heptane, chlorobenzene, paraxylene and m-dichlorobenzene decreased. Conclusions Through the GC-MS analysis of the exhaled breath of rats, eight components of VOCs in the exhaled breath of rats can be used as differential metabolites of radiation damage. This study lays a foundation for the establishment of a GC-MS analysis method for the components of VOCs in the exhaled breath of rats, as well as for the development of a nondestructive analytical assay for biological radiation damage.