[Comparative study of effects of nanosized and microsized silicon dioxide dust on mouse embryos]

To compare the effect of mouse embryonic toxicity between nanosized and microsized dioxide silicon, and detect the point mutation of Cx32 and Cx40 genes after the interference with nm-SiO2 and microm-SiO2 on pregnant mice.

Twenty-five male mice in 5 groups (control, microm-SiO2 50mg/m3, microm-SiO2 200mg/m3, nm-SiO2 50mg/m3, nm-SiO2 200mg/m3 groups) were treated through respiration from E0 to E17, study pregnant mice weights change trend, take out the embryos on E18, observe embryonic development circumstance and detect the point mutation of Cx32 and Cx40 genes with general PCR, PCR-SSCP methods.

Pregnant mice weights in all interfered groups were lower than that in control group on E18. Embryo numbers, living embryo numbers and embryo weights in all experimental groups had decreased in contrast with control. Living embryo numbers in nm-SiO2 200mg/m3 group had lessened comparing with nm-SiO2 50 mg/m3 and microm-SiO2 200mg/m3 groups. Embryo weights in nm-SiO2 200mg/m3 group reduced as compared with microm-SiO2 200mg/m3 group. Dead fetus frequency and absorbed fetus frequency in nm-SiO2 200mg/m3 group was higher statistically than control. Cx32 and Cx40 genes hadn't been found any point mutation.

Dioxide silicon had embryonic toxic effects on mouse, which was severe with nanosized diameter Nanosized dioxide silicon was also wondered to have embryonic mortality toxicity impact on mouse. There was no found point mutation toxicity on Cx32 and Cx40 genes for the two kind of researched material.