[Effects of bromopropane exposure on expression of DNA methyltransferases and level of histone acetylation in testis of male rats].

OBJECTIVE: To investigate the changes in the expression of DNA methyltransferases (DNMTs) and activities of histone acetyltransferase (HAT) and histone deacetylase (HDAC) in the testis of male rats exposed to bromopropanes (BPs). METHODS: Twenty-seven male rats were randomly divided into three groups to be intraperitoneally injected with 1-BP,2-BP, or corn oil (as a control) for two weeks. The sperm count and morphology in the epididymis were evaluated. The mRNA expression of DNMT1, DNMT3a, and DNMT3b and activities of HAT and HDAC in the testis were measured by quantitative real-time PCR and ELISA. RESULTS: Compared with the control group, the BP exposure groups showed significant decreased absolute and relative sperm counts; the proportion of tailless sperm increased in the 1-BP exposure group, while the proportion of sperm with abnormal heads increased in the 2-BP exposure group. The 2-BP exposure group had significantly lower mRNA expression of DNMT1, DNMT3a, and DNMT3b than the control group (P < 0.05). There were no significant differences in the activities of HAT and HDAC between the control group and 1-BP exposure group; the 2-BP exposure group showed significantly higher HAT activity than the control group (P < 0.05), but no significant difference was found in HDAC activity between them. CONCLUSION: Exposure to 2-BP might induce abnormal DNA methylation and histone acetylation, and epigenetic regulation might play an important role in the reproductive toxicity of 2-BP.