Abstract:

Objective To investigate the possible mechanism of PM2.5⁃induced reproductive dysfunction in rats. Method Thirtymale SD rats were randomly divided into normal saline control group，low concentration of PM2.5（PM 4.3 mg/mL）exposure group and high concentration of PM2.5（PM 12.9 mg/mL）exposure group，with 10 rats in each group. The suspension of PM2.5（dose：1 mL/kg）was given by intratracheal drip every 2 days. After successive 4 weeks，the growth of the rats was observed；the testis coefficient was calculated；the morphological changes of testicular tissue and cells were observed，and the serum testosterone content and the expression of protein related NF⁃κB inflammatory signal path were detected. Results Compared with those in the control group，testis weight and testis coefficient decreased in the experimental group. Light microscope found that in the experimental group，the wall of seminiferous tubule of testicular tissue in rats was thinner；spermatogenic cells at all levels were arranged loosely and disordered，and the number of mature sperm in the lumen decreased. Compared with that in the control group，the testosterone level in the experimental group was significantly decreased（P < 0.05）. Q⁃PCR results showed that the expression quantity of inflammatory factorIL ⁃ 6，and TNF ⁃ α mRNA in the experimental group were higher than those in the control group，and the differences were statistically significant（P < 0.05）. Western blotting showed that the expressions of protein IKK（IκB kinase），NF⁃κB，p⁃NF ⁃κB P65 and p⁃I κB⁃α related NF⁃κB signal path increased significantly when compared with the control group，and the differences were statistically significant（P < 0.05）. Conclusion PM2.5 may up ⁃ regulate the expression of IL ⁃ 6 and TNF ⁃ α through inducing NF⁃κB inflammatory signal path，then cause reproductive dysfunction in male rats.

Key words:

PM2.5, NF?κB, reproduetive dysfunction, infertility, rats, male