纳米TiO_2对子代大鼠免疫系统的毒性研究

Effects from exposure to nano-TiO_2 on the immune system of offspring of rats

目的:研究纳米二氧化钛(nano-TiO_2)对子代大鼠免疫系统的毒性。方法:实验分为nano-TiO_2组和对照组,每组45只SD大鼠(雌鼠30只、雄鼠15只)。染毒组每天给予250 mg/kg的nano-TiO_2混悬液,对照组每天灌胃给予等体积生理盐水,灌胃2周后进行交配,各组雌鼠在交配期、妊娠期、哺乳期继续灌胃染毒。F1代子鼠从离乳到处死持续灌胃染毒。在子鼠出生后第56天进行免疫毒性评价,指标包括免疫器官(肝、脾和胸腺)脏器系数、脾和潘氏淋巴结淋巴细胞分型、脾抗体生成细胞检测。结果:与对照组比较,nano-TiO_2组F1代雌鼠脾脏系数升高,而雄鼠肝脏系数降低,差异均有统计学意义(P均<0.05),但病理学检查未发现异常;淋巴细胞分型和抗体生成细胞试验结果的差异均无统计学意义(P均>0.05)。结论:在本试验条件下,Nano-TiO_2对F1代子鼠免疫系统功能未见明显不良影响。

OBJECTIVE:To explore the effects from exposure to nano-TiO2 on the immune system of offspring of rats.METHODS:SD rats were divided into nano-TiO2 and control groups with 30 females and 15 males in each group.Exposed groups were given nano-TiO2 by gastric filling method at the doses of 250 mg/kg,and the control group was given equal volume of NaCl.The exposure was continued for 2 weeks before mating,and throughout pregnancy and lactation.Offspring were infused nano-TiO2 or NaCl into stomach from weaning to execution.Immune function of offspring was observed on PND56.Observation indexes included organ coefficients of liver,spleen and thymus,and splenic and paneth lymphocyte typing and antibodyproducing cell assay.RUSULTS:Organ coefficients of spleen in the nano-TiO2 treated female rats group were significantly higher than that of the control group(P<0.05).Organ coefficients of liver in nano-TiO2 treated male rats group were significantly lower than that of the control group(P<0.05).However,no abnormalities were found in histopathological examinations.No differences were observed on lymphocyte typing and antibodyproducing cell assays between the nano-TiO2 and the control groups(P>0.05).CONCLUSION:The result suggests that,under the present experimental conditions,nano-TiO2 has no effect on the immune system of offspring of rats.