Irradiation-induced apoptosis of mouse bone marrow stromal cells.

OBJECTIVE: To study the apoptotic patterns of bone marrow stromal cells (BMSCs) after irradiation. METHODS: Apoptosis of BMSCs induced by (60)Co gamma irradiation was detected by both flow cytometry and electron microscopy. RESULTS: Compared with normal control group, no manifest changes in the apoptosis ratio occurred in BMSCs after 50 Gy irradiation (P>0.05) as demonstrated by flow cytometry. Four hours after 100 Gy irradiation, manifest changes in apoptosis ratio of BMSCs were observed (P<0.01), reaching the peak 20 h later. Similar apoptotic patterns occurred in BMSCs exposed to irradiation of 200 Gy (P>0.05), only the apoptosis ratio was slightly higher. CONCLUSION: Irradiation of proper dose may induce apoptosis in vitro in BMSCs that possess strong resistance to irradiation.