对实验所用纳米二氧化钛的粒径、形状、晶型和溶液体系中的团聚程度等物理化学性质进行详细表征。80只4周龄清洁级SD大鼠按体质量随机分为8组(每组10只,雌雄各半)。每天灌胃给予0、2、10、50 mg/kg纳米二氧化钛,分别加或不加1.8 g/kg葡萄糖。染毒90 d后进行血清叶酸和维生素B 12含量检测。
纳米二氧化钛晶型为锐钛矿,近球形,平均粒径为(24±5) nm。在雄性幼年大鼠中,与对照组相比,纳米二氧化钛(10 mg/kg)加葡萄糖染毒可导致血清叶酸浓度明显增加,差异具有统计学意义( P<0.05)。在雌性和雄性幼年大鼠中,与单纯葡萄糖(1.8 g/kg)染毒组相比,高剂量纳米二氧化钛(50 mg/kg)加葡萄糖可导致血清叶酸浓度明显降低,差异具有统计学意义( P<0.05)。经过联合作用分析,纳米二氧化钛与葡萄糖联合暴露对雌性幼年SD大鼠血清叶酸浓度的影响存在明显拮抗作用。纳米二氧化钛与葡萄糖联合暴露对幼年SD大鼠血清维生素B 12浓度的影响较小,未见明显交互作用。仅发现与单纯葡萄糖(1.8 g/kg)染毒组相比,雄性大鼠低剂量(2 mg/kg)纳米二氧化钛加葡萄糖染毒组血清维生素B 12浓度明显上升,差异具有统计学意义( P<0.05)。
To explore the effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B 12 in young SD rats.
At first, the physical and chemical properties of titanium dioxide nanoparticles, such as particle size, shape, crystal form and agglomeration degree in solution system, were characterized in detail. Eighty 4-week-old young SD rats were randomly divided into 8 groups (10 rats in each group, half male and half female). The rats were exposed to titanium dioxide nanoparticles through intragastric administration at 0, 2, 10 and 50 mg/kg body weight with or without 1.8 g/kg glucose daily for 90 days. At last, the concentrations of serum folate and vitamin B 12 were detected.
Titanium dioxide nanoparticles were anatase crystals, closely spherical shape, with an average particle size of (24±5) nm. In male young rats, compared with the control group, the serum folate concentration was significantly increased when exposed to titanium dioxide nanoparticles (10 mg/kg) and glucose. The difference was statistically significant ( P<0.05). However, in female and male young rats, compared with glucose (1.8 g/kg) exposure group, titanium dioxide nanoparticles (50 mg/kg) and glucose significantly reduced the serum folate concentration. The difference was statistically significant ( P<0.05). Through statistical analysis of factorial design and calculation of interaction, obvious antagonistic effect was observed between titanium dioxide nanoparticles and glucose on the serum folate concentration in the young female SD rats. The combined oral exposure of titanium dioxide nanoparticles and glucose had little effect on the concentration of serum vitamin B 12 in the young SD rats, with no significant interaction between the two substances. It was only found that titanium dioxide nanoparticles (2 mg/kg) and glucose significantly increased the serum vitamin B 12 concentration, compared with glucose (1.8 g/kg) exposure group. The difference was statistically significant ( P<0.05).