致死剂量辐射诱导小鼠骨髓细胞凋亡特征的研究

STUDIES ON THE CHARACTERISTICS AND SIGNIFICANCE OF HEMATOPOICTIC CELLS APOPTOSIS IN IRRADIATION MOUSE BONE MARROW

经60Coγ射线以不同剂量全身照射213只LACA小鼠，于照射后4周内分批活杀，将骨髓标本分别进行H．E染色、半薄及超薄切片，并通过原位末端标记和DNA凝胶电泳观察其生化特征。结果表明：照射后6h，各剂量组小鼠骨髓造血细胞出现凋亡明显增多，且照射剂量越大，凋亡细胞越多。凋亡的细胞形态上表现为染色质浓缩、边移，呈半月型、环状或不规则状，核碎片及凋亡小体形成，电泳下可见DNA梯状图谱。在2．5～7．0Gy照射范围内，凋亡是辐射诱导造血细胞死亡的主要方式。

213 LACA mice were irradiated respectively with dose of 2.5, 4.0, 5.5 and 7.0 Gy γ-rays and sacrificed within 4 weeks after radiation. By means of light and electron microscopy, in situ terminal labeling and biochemical analysis apoptotic hematopoietic cells apoptosis were investigated in irradiated mouse bone marrow. The results showed: Much more apoptotic cells were found in each irradiated group bone marrow at 6 h after radiation. Furthermore, the higher radiation dose was, the more apoptotic cells were. The characteristics of apoptotic cells were the chromatin condensation and margination, just as half-moon, ring-like or irregular shapes. The nucleus may be break up and became apoptotic bodies. There was DNA degradation of apoptotic cells detected by in situ terminal labeling and DNA ladder formation in agarose gel electrophoresis. Conclusion: At the range of 2.5 to 7.0Gy irradiation, apoptosis is tile main pathway for radiation-induced hematopoietic cells death.