The Preliminary Study In Effects Of Diesel Exhaust Collection On Mice Embryonic Development

Objective:To establish the pregnant mice model of exposure to diesel exhaust particles, and to investigate effects of diesel exhaust particles on mice embryonic development.Methods:Diesel exhaust particles were prepared. Healthy adult Kunming mice were mated(female:male=2:1), and the morning of appearance of a vaginal plug was taken as 0.5 day(0.5d) of pregnancy.Pregnant mice were randomly divided into three groups, namely, high dose group(7.5mg/kg), low dose group(4.5mg/kg) and control group(0mg/kg), and were injected intraperitoneally with diesel exhaust particles daily from the 0.5d to the 18.5d of pregnancy. On the 18.5d of pregnancy, all pregnant mice were sacrificed after been weighted. The uteri were cut open to examine the pregnancy condition and the fetal development condition. Meanwhile, live fetal heart, lung, kidney and placenta were measured and their pathological changes were examined.Results:Diesel exhaust particles can cause mice adverse pregnancy outcomes. The rate of absorbed fetuses in the high dose group was higher than that in the control group, and the rate of live fetuses was lower. Diesel exhaust particles cause live fetal external appearance malformation, such as open eyes, prominent eyes, short limbs. The live fetal body length, total fetal body weight and female fetal body weight were significantly decreased in the high dose group. The rate of intrauterine growth retardation (IUGR) was significantly increased, and the female IUGR fetuses were more than the male IUGR fetuses. The live fetal organ coefficients of hearts and kidneys in the high dose group were all significantly decreased. Moreover, in the exposure group the live fetal placentas showed severe histopathological changes, such as congestion, trophoblastic vacuolar degeneration. And there were pulmonary emphysema, congestion and inflammatory cell infiltration in the live fetal lungs. Their hearts showed struction disorder, cardiac cell edema and steatosis, accompanied by congestion. The inflammatory cell infiltration, and vacuslation, steatosis and granular degeneration of the renal tubular epithelial cells were observed in histo logical sections of the live fetal kidneys.Conclusion:Diesel exhaust particles cause placentas severe histopathological changes and weight decrease, may affect the placenta development and function, resulting in adverse pregnancy outcomes, such as absorption, death, appearance malformations and IUGR. Additionally, diesel exhaust particles may enter into the fetus through the placenta, and make live fetal internal organs histopathological changes, then hinder live fetal interal organs develop.