Abstract: Objective To elucidate the effects of epigallocatechin-3-gallate(EGCG)on protein arginine methyltransferase 1(PRMT1), dimethylarginine dimethylaminohydrolases(DDAH), asymmetrical dimethylarginine(ADMA), and nitric oxide synthase(NOS)pathway in corpus cavernosum of aged rats, and to investigate the possible mechanisms. Methods A total of 30(erectile dysfunction)ED rats were screened among 40 18-month-old male SD rats, and randomly divided into the aged group(n=10), small dose group(daily gavage feedings of EGCG at doses of 10 mg/kg for 12 weeks, n=10)and large dose group(daily gavage feedings of EGCG at doses of 100 mg/kg for 12 weeks, n=10). Another 10 3-month-old rats served as controls. After 12 weeks, the maximal intracavernous pressure(Max ICP), mean arterial blood pressure(MAP)and Max ICP/MAP were determined. The animals were then sacri- 山 东 大 学 学 报 (医 学 版)54卷5期 -陈东,等.EGCG对老龄大鼠阴茎组织中PRMT1、DDAH、ADMA、NOS通路的影响 \=-ficed to harvest penis tissues. PRMT1, DDAH and NOS levels were detected with Western blotting and immunohistochemistry. ADMA and cGMP levels were assessed with ELISA. The MDA level and SOD activity were also detected. Results Compared with the control group, the aged group had decreased Max ICP/MAP, DDAH, NOS, cGMP and SOD activity(all P<0.05). Compared with the aged group, small and large dose group had significantly increased Max ICP/MAP, SOD activity, cGMP, DDAH and NOS levels, but decreased MDA, ADMA, and PRMT1(all P<0.05). Conclusion EGCG treatment could ameliorate erectile function in aged rats via upregulating PRMT1, DDAH, ADMA and NOS pathway and inhibiting oxidative stress.

Key words: Asymmetrical dimethylarginine, Dimethylarginine dimethylaminohydrolases, Epigallocatechin-3-gallate, Erectile dysfunction, Protein arginine methyltransferase 1