大气细颗粒物PM2.5对雌性大鼠生育力损伤作用的研究

目的：观察大气细颗粒物PM2.5对雌性大鼠生育力的毒性作用。方法：采用气管滴注方法，将生理盐水、低、中、高剂量PM2.5混悬液对SD雌性大鼠染毒，以苯并a]芘（BaP）溶液灌胃作为阳性对照。染毒时间为孕前15 d至孕后6 d，孕前15 d每3天称量1次雌鼠体质量。在孕6.5 d（GD6.5）处死大鼠，观察整肺外观，记录胚胎个数、子宫质量（含胚胎，称子宫连胚质量）。取静脉血测量重金属铅（Pb）、汞（Hg）、镉（Cd）、砷（As）、锑（Sb）含量。HE染色用于子宫及卵巢组织病理学检查。结果：与生理盐水组相比，高剂量PM2.5组大鼠体质量下降明显、肺部外观改变明显；随着PM2.5染毒剂量的升高，雌鼠的交配指数及GD6.5受孕指数下降；BaP组雌鼠的GD6.5受孕指数无变化，但GD19.5受孕指数下降；PM2.5低、中、高剂量组大鼠胚胎个数减少，子宫连胚质量下降；PM2.5低、中、高剂量组大鼠外周血As的浓度升高，As、Sb的浓度与大鼠胚胎个数呈负相关；未发现PM2.5低、中、高剂量组大鼠卵巢和子宫组织有明显的病理学改变。结论：PM2.5对雌性大鼠的生育力具有损伤作用，这与PM2.5表面载带的重金属As、Sb的毒性作用有关；BaP损害植入后胚胎的生存力。

Impairment of Airborne Fine Particulate Matters PM2.5 to the Fertility of Female Rats

Objective:To explore the toxicity of fine particulate matter (PM2.5) on the fertility of female rats. Methods:Adult female SD rats were randomly divided into 5 groups:saline group (as negative control), low- , middle- and high-dose PM2.5 groups, and BaP group (as positive control). PM2.5 was given by trachea instillation and BaP was given by intra-gastric administration from 15 days pro-gestation to 6 days after gestation. On the gestational day 6.5 (GD6.5), female rats were sacrificed. Lungs were observed by naked eye. Uterine weight and embryos counts were recorded. Vein blood was collected for detecting the concentration of blood heavy metals including lead (Pb), mercury (Hg), cadmium (Cd), arsenic (As) and antimony (Sb). Tissues of uterus and ovaries were stained by HE. Results:Compared with the saline group, body weight of rats in the high-dose PM2.5 group significantly decreased and the lung histology also changed. While the dose of PM2.5 raised, the mating and GD6.5 pregnancy index decreased nevertheless rats in BaP group showed no difference. Then GD19.5 pregnancy index of BaP group decreased apparently as compared with saline group. Embryos counts,uterine and embryos weight in three PM2.5 groups significantly reduced. The As level increased in the three PM2.5 groups, which negatively related to the number of embryos,as well as Sb level. There was no significant change in pathology of uterine or ovarian tissue. Conclusions:PM2.5 could impair the fertility of female rats, and the increased As and Sb levels could be related to the reproductive toxicity. BaP impairs the viability of implanted embryos.