Objective
To study and compare the effects of short-term oral exposure to titanium dioxide (TiO2) nanoparticles and microparticles on the absorption of iron and glucose in small intestine of young rats.
Methods
Forty-two male SD rats (4 weeks old) were randomly divided into seven groups. The exposed rats were orally treated with 2, 10, 50 mg/kg (in terms of body weight) TiO2 nanoparticles or microparticles (average original particle size:24 nm or 120 nm), respectively, once a day for consecutive 14 days, and the control group was administered with distilled water at the same volume. Everted gut sac model was utilized to study the small intestinal absorption of iron and glucose with supplement of 20 mmol/L glucose solution and 20 mmol/L ferrous sulfate (FeSO4) solution.
Results
Compared to the control group, the small intestines of rats in both the TiO2 nanoparticle groups and the TiO2 microparticle groups didn't show any obvious pathological changes after the 14-day oral treatment. The cumulative glucose and iron absorption tended to increase with the extension of time in all groups. The rate and amount of iron and glucose absorbed in both TiO2 nanoparticle and microparticle groups were slightly higher than those of the control group, but the differences were not statistically significant (P > 0.05). At the same time point, the rate and amount of iron and glucose cumulative absorption didn't show a doseresponse relationship, and there were no significant differences in the different dose groups (Fcumulative iron absorption=0.674, Frate of iron absorption=0.674; Fcumulative glucose absorption=1.332, Frate of glucose absorption=1.545; Ps > 0.05). Under the same exposure dose, no differences in the rate and amount of iron and glucose absorbed were found between the TiO2 nanoparticle and microparticle groups (Ps >0.05).
Conclusion
Short-term oral exposure to TiO2 nanoparticles and microparticles shows no obvious influence on the small intestinal absorption of iron and glucose in young rats, and there is no noticeable difference between TiO2 nanoparticle and microparticle groups.
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