Homocysteine and copper interact to promote type 5 phosphodiesterase expression in rabbit cavernosal smooth muscle cells  

作　　者：Matthew Hotston Jamie Y. Jeremy Jonathon Bloor Nick S. Greaves Raj Persad Gianni Angelini Nilima Shukla 

机构地区：[1]Department of Urology University of BristoL Bristol BS8 1TH, UK [2]Department of Cardiac Surgery, University of BristoL Bristol BS8 1TH, UK

出　　处：《Asian Journal of Andrology》2008年第6期905-913,共9页亚洲男性学杂志（英文版）

摘　　要：Aim： To study the effects of homocysteine and copper on type 5 phosphodiesterase （PDE5） expression in cavemosai vascular smooth muscle cells （CVSMCs） and to investigate superoxide （O2-） derived from nicotinamide adenine dinucleotide phosphate oxidase as homocysteine and copper generate O2-, and O2- upregulates PDE5 expression. Methods： CVSMCs derived from rabbit penis were incubated with homocysteine or copper chloride with or without superoxide dismutase （SOD）, catalase, sildenafil citrate, or apocynin （nicotinamide adenine dinucleotide phosphate inhibitor） for 16 h. The expression of PDE5 and of glyceraldehyde-3-phosphate dehydrogenase （internal standard） was assessed using Western blot analysis. In parallel, O2-was measured spectrophotometrically. Results： CuCl2 alone （up to 10 μmol/L） and homocysteine alone （up to 100 μmol/L） had no effect on O2- formation in CVSMCs compared to controls. In combination, however, homocysteine and CuCl2 markedly increased O2- formation, an effect blocked by SOD, catalase, apocynin, and sildenafil （1 μmol/L） when co-incubated over the same time course. PDE5 expression was also significantly increased in CVSMCs incubated with homocysteine and CuCl2, compared to controls. This effect was also negated by 16-h co-incubation with SOD, catalase, apocynin and sildenafil. Conclusion： This represents a novel pathogenic mechanism underlying ED, and indicates that the therapeutic actions of prolonged sildenafil use are mediated in part through inhibition of this pathway.Aim： To study the effects of homocysteine and copper on type 5 phosphodiesterase （PDE5） expression in cavemosai vascular smooth muscle cells （CVSMCs） and to investigate superoxide （O2-） derived from nicotinamide adenine dinucleotide phosphate oxidase as homocysteine and copper generate O2-, and O2- upregulates PDE5 expression. Methods： CVSMCs derived from rabbit penis were incubated with homocysteine or copper chloride with or without superoxide dismutase （SOD）, catalase, sildenafil citrate, or apocynin （nicotinamide adenine dinucleotide phosphate inhibitor） for 16 h. The expression of PDE5 and of glyceraldehyde-3-phosphate dehydrogenase （internal standard） was assessed using Western blot analysis. In parallel, O2-was measured spectrophotometrically. Results： CuCl2 alone （up to 10 μmol/L） and homocysteine alone （up to 100 μmol/L） had no effect on O2- formation in CVSMCs compared to controls. In combination, however, homocysteine and CuCl2 markedly increased O2- formation, an effect blocked by SOD, catalase, apocynin, and sildenafil （1 μmol/L） when co-incubated over the same time course. PDE5 expression was also significantly increased in CVSMCs incubated with homocysteine and CuCl2, compared to controls. This effect was also negated by 16-h co-incubation with SOD, catalase, apocynin and sildenafil. Conclusion： This represents a novel pathogenic mechanism underlying ED, and indicates that the therapeutic actions of prolonged sildenafil use are mediated in part through inhibition of this pathway.

关 键 词：erectile dysfunction superoxide PDE5 SILDENAFIL 

分 类 号：R698[医药卫生—泌尿科学]