标题：Epigallocatechin-3-gallate ameliorates erectile function in aged rats via regulation of PRMT1/DDAH/ADMNOS metabolism pathway
作者：Chen, Dong; Zhang, Ke-Qin; Li, Bo; Sun, Ding-Qi; Zhang, Hui; Fu, Qiang
作者机构：[Chen Dong] Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, China.;[Zhang Keqin] Depart 更多
通讯作者地址：[Fu, Q]Shandong Univ, Dept Urol, Shandong Prov Hosp, Jinan 250021, Shandong, Peoples R China.
关键词：asymmetrical dimethylarginine; dimethylarginine dimethylaminohydrolase;; epigal locatechi n-3-gallate; erectile dysfunction; oxidative stress;; protein arginine methyltransferases 1
摘要：Aging-related ED is predominantly attributed to neurovascular dysfunction mediated by NO suppression and increased oxidative stress in penis. The alterations of protein arginine methyltransferases 1 (PRMT1)/dimethylarginine dimethylaminohydrolase (DDAH)/ asymmetrical dimethylarginine (ADMA)/NO synthase (NOS) pathway regulate NO production in the vascular endothelium. Epigallocatechin-3-gallate (EGCG) is one of the most abundant and antioxidative ingredients isolated from green tea. In the present study, 40 Sprague-Dawley rats were randomly distributed into four groups: one young rat group and three aged rat groups treated with daily gavage feedings of EGCG at doses of 0, 10 mg kg(-1), and 100 mg kg(-1) for 12 weeks, respectively. Erectile function was assessed by electrical stimulation of the cavernous nerves with intracavernous pressure (ICP) measurement. After euthanasia, penile tissue was investigated using Western blot and ELISA to assess the PRMT1/DDAH/ADMA/NOS metabolism pathway. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected by colorimetry. We also evaluated smooth muscle contents. The ratio of maximal ICP and mean systemic arterial pressure (MAP) was markedly higher in EGCG-treated aged rats than in untreated aged rats. We found that DDAH 1 and DDAH2 were expressed in cavernosal tissue, and they were downregulated in corpora of aged rats. The administration of EGCG upregulated the expression and activity of DDAH. In contrast, EGCG treatment downregulated the expression of PRMT1 and ADMA content. Moreover, EGCG-treated rats showed an improvement in smooth muscle expression, the ratio of smooth muscle cell/collagen fibril, SOD activity, and MDA levels when compared with untreated aged rats.