气动雾化法吸入PM2.5模拟物对小鼠妊娠的影响

Effects of simulated PM2.5 on gestation of mice in pneumatic nebulization method

通过不同质量浓度的PM2.5暴露,探讨自然呼吸条件下其对受孕小鼠妊娠情况、胎盘结构及胚胎发育等的影响.将32只健康清洁级雌性昆明小鼠随机分为空白组、对照组、低剂量组和高剂量组.各组受孕成功后于胚胎期0.5~15.5 d进行6h/d暴露处理,至胚胎期16.5 d剖杀所有孕鼠,记录妊娠情况、取胎盘和胚胎组织称重、对胚胎进行尾长和体长的测定,通过组织切片观察胎盘结构变化,检测抗氧化能力指标.结果表明,PM2.5低剂量组和高剂量组暴露造成孕鼠体重(特别是妊娠后期)、胎盘和胚胎重量、胚胎尾长与体长增长率均极显著降低(P<0.01);PM2.5高剂量组暴露导致胎盘迷路区组织学改变,胎盘及胚胎抗氧化能力极显著降低(P<0.01).PM2.5通过呼吸途径不仅能够影响孕鼠母体体况,而且可能造成孕鼠不良妊娠,具有一定的胚胎毒性.

The paper aimed to investigate into pregnant mice’s gestation situation,structural changes in placenta and oxidative stress of foetus after different concentrations of PM2.5 exposure.32 female Kunming mice were randomly divided into 4 groups,including a blank group,control group,low dose group and high dose group.The female mice were mated with male ones until ingravidation.With exposure in different conditions from embryonic day 0.5 to 15.5.On embryonic day 16.5,all the pregnant mice were killed,and the gestation situation was recorded,placentas and foetuses were removed and weighted,length of every foetus’tail and body were measured at the same time.The microscopic structural changes of placenta were observed by histologic section,and finally,the indexes of antioxidant ability were measured by kits.The result shows that exposure to PM2.5 led to ponderal decrease(especially in later period of gestation)in placenta and foetuses,length of tail and body growth rate,and the difference was highly significant(P<0.01).The structure of labyrinth in placenta was changed in the high dose group,and the antioxidant ability of placenta and foetus was reduced highly significantly(P<0.01).PM2.5 not only influenced pregnant mice’s body condition,but also might cause adverse pregnancy,illustrating that PM2.5 has definite embryotoxicity in mice.