Effects of Ginkgo biloba extracts with mirodenafil on the relaxation of corpus cavernosal smooth muscle and the potassium channel activity of corporal smooth muscle cells  

作　　者：Jung Jun Kim Deok Hyun Han Soo Hyun Lim Tae Hun Kim Mee Ree Chae Kyung Jin Chung Sung Chul Kam Ju-Hong Jeon Jong Kwan Parks Sung Won Lee 

机构地区：[1]Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seou1135-710, Korea [2]Department of Urology, Gachon University Gil Hospital, Incheon 405-760, Korea [3]Department of Urology, Gyeengsang National University College of Medicine, Gyeongsangnam-do 660-702, Korea

出　　处：《Asian Journal of Andrology》2011年第5期742-746,共5页亚洲男性学杂志（英文版）

摘　　要：In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1 × 10^-5 mol I^-1 norepinephrine, GBE （0.01-1 mg ml^-1） and mirodenafil （0.01-100 nmol I^-1） were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavemosum was relaxed in response to GBE in a dose-dependent manner （from 0.64%±8.35% at 0.01 mg ml^-1 to 52.28%±11.42% at 1 mg ml^-1）. After pre-treatment with 0.03 mg ml^-1 of GBE, the relaxant effects of mirodenafil were increased at all concentrations, After tetraethylammonium （TEA） （1 mmol I^-1） administration, the increased effects were inhibited （P〈0.01）. Extracellular administration of GBE increased the whole-cell K^＋ outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by I mmol 1-1 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K＋ flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1 × 10^-5 mol I^-1 norepinephrine, GBE （0.01-1 mg ml^-1） and mirodenafil （0.01-100 nmol I^-1） were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavemosum was relaxed in response to GBE in a dose-dependent manner （from 0.64%±8.35% at 0.01 mg ml^-1 to 52.28%±11.42% at 1 mg ml^-1）. After pre-treatment with 0.03 mg ml^-1 of GBE, the relaxant effects of mirodenafil were increased at all concentrations, After tetraethylammonium （TEA） （1 mmol I^-1） administration, the increased effects were inhibited （P〈0.01）. Extracellular administration of GBE increased the whole-cell K^＋ outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by I mmol 1-1 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K＋ flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.

关 键 词：calcium-activated potassium channels erectile dysfunction Ginkgo biloba phosphodiesterase inhibitors smooth muscles 

分 类 号：Q2-33[生物学—细胞生物学] TS202.3[轻工技术与工程—食品科学]