【摘要】 两次给小鼠腹腔注射硝酸钬溶液,相间24h,第二次注射24h后取股骨骨髓涂片,同时取肝脏检测超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活力。结果发现,在(10～40)mg/kg·bw剂量范围内,微核率和三种酶的活力随剂量的增加而升高;当剂量升至80mg/kg·bw时,三种酶活力趋于下降,但仍高于阴性对照组,而微核率增加到最大值;当剂量升至160mg/kg·bw时,微核率和酶活力均低于阴性对照组。低剂量(<40mg/kg·bw)硝酸钬溶液可促进骨髓细胞增殖,高浓度则表现出抑制作用。实验中还观察到核异常程度随剂量的增加而上升。推测低剂量钬离子通过诱导小鼠机体三种抗氧化酶活力的升高,清除部分自由基,一定程度上减轻了染色体损伤,高剂量则抑制了细胞分裂指数,又降低小鼠体内抗氧化酶活力,从而促进核异常。更多还原

【Abstract】 Holmium nitrate solution was administered intraperitoneally twice with interval of 24 hours.Smears were prepared with bone-marrow cells of thighbone 24 hours after the second injection,while antioxidant enzymes activities of superoxide dismutase(SOD),catalase(CAT) and peroxidase (POD) of livers were tested.The results showed that,when the concentration between 10mg/kg·bw and 40mg/kg·bw,the frequency of micronuclei and activities of SOD,CAT and POD arose with the increase of concentrations;when the concentration is further increased to 80mg/kg·bw,three enzymes’ activities began to decline,but were still higher than those of control group,meanwhile the micronuclei frequency rose to maximum;when the concentration reached to 160mg/kg·bw,both the enzymes’ activities and micronuclei frequency declined to be lower than those of control group.The experiment also found that the proliferation indices of bone-marrow cells were accelerated in lower concentration (below 40mg/kg·bw),but repressed in higher concentration,and that the extension of anomalous nuclei were increased with the concentration.It is possible that low dose of holmium ions could get rid of free radicals by increasing three antioxidant enzymes’ activities,which reduced chromosome’s damage by free radicals in some degree,and that high dose of holmium ions repressed both the mitosis indices and three antioxidant enzymes’ activities and promoted nuclei anomaly.更多还原