The Research On Exposure To Airborne Particulate Matter PM_2.5 Influencing Abnormalities Of Ovarian Function In SD Rats

ObjectiveThe present study was to investigate the relationship between exposure to different levels（sex hormone,ovarian reserve,ovarian toxicity）of PM_2.5 suspension Fuzhou region,on the development of ovarian in SD rat.This research provides a theoretical basis for the influence of environment on female reproduction health,which makes it to develop effective protection measures.MethodsThirty-two SD rats were randomly allocated to control group,5mg/kg PM_2.5 group,10mg/kg PM_2.5 group and 20mg/kg PM_2.5 group.These rats were anesthetized,intubated,and submitted to the instillation of PBS or the following PM_2.5 suspension at different concentrations:20mg/ml,40mg/ml and 80mg/ml,once every three days,lasting 4 weeks.These rats were prohibitted drinking water within 24 hours after the last instillation.Female rats serum estradiol（E₂）by ELISA,progesterone（P）,luteinizing hormone（LH）,follicle-stimulating hormone（FSH）,anti m ü llerian hormone（AMH）.Determination of ovarian wet weight and organ coefficient of ovaries.H & E staining by measuring the number of follicles at various levels were observed in rat ovarian tissue pathological changes,ultrastructural changes of ovary were observed by electron microscope.Results（1）The ovarian wet weight and organ coefficient of ovaries of the middle dose group and the high dose groups were lower than that of the control group,with no dose effect relationship with PM_2.5.（2）E₂ levels of the Low,medium and high dose groups were significantly lower than that of the control group,with statistical significance（P<0.05）,and the degree of reduction in E₂ levels showed a significant dose effect relationship with PM_2.5.（3）P levels of the Low,medium and high dose groups were significantly lower than that of the control group,with statistical significance（P<0.05）,but the degree of reduction in P levels showed no significant dose effect relationship with PM_2.5.（4）FSH levels of the medium and high dose groups were higher than that of the control group significantly（P<0.05）,but FSH levels of the low dose group were close to that of the control group.FSH levels of the Low,medium and high dose group increased gradually（P<0.05）,which showed a clear dose-response relationship.（5）LH levels of the low,middle and high dose groups were close to that of the control group,without significant change（P>0.05）.（6）AMH levels of the middle and high dose groups were lower than that of the control group significantly（P<0.05）.AMH levels of the high dose group were close to that of the middle group（P>0.05）,which showed no dose-response relationship between the reduction in AMH levels and PM_2.5.（7）In the different dose groups,the constituent ratios of primordial follicle,primary follicle,mature follicle did not change significantly.The proportions of the secondary follicle in medium and high dose group were significantly lower than that of the control group,which was statistically significant（P<0.05）.There was no significant difference between the low dose group and the control group in the proportions of the secondary follicl（P>0.05）.The proportions of atresic follicles in low,middle and high dose group were significantly higher than that of the control group.There was statistically significant difference（P<0.05）,but the degree of follicular atresia is not a dose-response relationship.The constituent ratio of corpus luteum in the control group,which was close to that of the low and middle dose group（P>0.05）,was lower than that of the high dose group（P<0.05）.Compared with control group,the ovarian pathology in the low,middle,high dose group were seen at all levels of development of follicles,ovarian tissue without obvious pathological changes.Compared with the control group,the number of atretsic follicles of low,middle dose group was obviously increased.The number of atresic follicles inthe high dose group increased significantly.Various doses of ovarian function bubble cell mitochondrial swelling and follicle cell in medium and high groups,dose of PM_2.5 apoptosis and even death was found by transmission electron microscope.Conclusions（1）The exposure to different doses of PM_2.5 can cause the increase of FSH level and the decrease of ovary wet weight organ coefficient,E₂ level,P level and AMH level,which suggested that exposure to PM_2.5 may directly or indirectly lead to abnormal ovarian function in SD rats,maybe ovarian failure and reproductive function.（2）The exposure to different doses of PM_2.5 did not change the constituent ratios of primordial follicle,primary follicle and mature follicles significantly.The numbers of secondary follicles in the medium and high does group were significantly lower than that the control group.The number of luteum in the high does group was higher than that of the control group.The proportions of atresic follicle in different does group were significantly higher than that of control group.（3）No obvious pathological change was found in the ovarian tissues of different doses groups,but there was a significant increase in the numbers of atresia in the high dose group.Different dose of PM_2.5 exposure ovarian cell,s ultra structure changes and exposure in medium and high groups,dose of PM_2.5 can cause follicular cell apoptosis and even death.