造血干细胞辐射损伤和修复的研究Ⅳ.——苯甲酸雌二醇对小鼠造血干细胞辐射损伤和修复的影响

小鼠于照前7天由肌内注射苯甲酸雌二醇,根据骨髓粒系祖细胞(CFU-D),内源性脾结节(CFU-S),以及骨髓细胞分裂指数和染色体畸变率的改变,探讨其对受照射小鼠造血功能的影响。在照射后的早期,不论CFU-D的数量或染色体畸变率,用药与对照组之间均未见有差异,而在照射后的第3、5、9天,给药组CFU-D的产率均比不用药的对照组有明显提高,而且,骨髓细胞分裂指数在照后3～5天亦高于对照组。上述结果提示,苯甲酸雌二醇的辐射防护作用主要不在减轻造血干细胞的辐射损伤,而与促进残存干细胞增殖有关。

RADIATION DAMAGE AND RECOVERY OF HEMOPOIETIC STEM CELLS IV. THE EFFECT OF BENZOATE ESTRADIOL ON DAMAGE AND RECOVERY OF HEMOPOIETIC STEM CELLS IN IRRADIATED MICE

The effect of benzoate estradiol on hemopoiesis in irradiated mice was studied withassays of granulocyto-macrophage progenitic cells (CFU-D) and endogenous spleencolonies (CFU-S) in bone marrow and simultaneous determinations of mitotic index andfrequency of chromosomal aberrations of bone marrow cells, after a single intramuscularinjection of benzoate estradiol 7 days before irradiation.in the initial stage postirradiation, no significant difference was found between thr mean values neither the number of CFU-D nor the frequncy of chromosomal aberrations of both groups , whereas on the 3th, 5th and 9th day, the production of CFU-D of the pretrated group was increased markedly than that of non-treated control group. In addition, a significant increase in the mitotic index of bone marrow cells was observed by days 3-5 postirradiation in pretreated group.These observations suggest that benzoate estradiol provoke an enhancement of prol -eferation of residual stem cell , srather than a decrease its radiosensetivity.