cGMP特异性磷酸二酯酶5活性及其抑制剂的研究  

Research of the activity and the inhibitors of cGMP specific PDE5

作　　者：郝顺祖[1] 黄诒森[1] 张均田[2] 

机构地区：[1]镇江医学院生物化学研究室,江苏镇江212001 [2]中国医学科学院药物研究所,北京100050

出　　处：《中国生化药物杂志》2001年第3期144-146,共3页Chinese Journal of Biochemical Pharmaceutics

摘　　要：目的研究以cGMP为特异底物的磷酸二酯酶 5 (PDE5 )的水解酶活性及PDE5选择性抑制剂西地那非(sildenafil)的抑制作用。方法以牛阴茎海绵体为原料 ,通过快速蛋白液相系统分离纯化得到PDE同工酶 ,然后以3 H cGMP为底物 ,经纯化的PDE同工酶催化水解为3 H GMP ,进一步在含 5′ 核苷酸酶的蛇毒液作用下 ,脱去 5′ 磷酸生成3 H 鸟苷 ,在闪烁剂激发下测定3 H 鸟苷的变化 ,绘制PDE活性曲线。以不同剂量的PDE5选择性抑制剂西地那非作用于PDE5 ,经DixonPlots法处理结果以观察西地那非的抑制效应。结果由牛阴茎海绵体纯化得到三个PDE同工酶峰 ,其中第三个峰对cGMP水解活性最强 ,且西地那非对第三峰抑制作用明显。结论海绵体中的PDE以cGMP 特异的PDE5为主 ,西地那非是PDE5的选择性抑制剂 ,通过以上实验观察可初步确定第三峰为PDE5 ,其结果与文献报道相符。PurposeThe aim is to study the activity and the sildenafil selective inhibition of PDE5. MethodsThe PDE isoenzymes were purified from bovine penis corpus cavernosum tissue by FPLC system. PDE activity was assayed by using 3H-cGMP as substrate, the PDE isoenzymes hydrolyzed it to 3H-GMP, and 3H-GMP was further hydrolyzed to 3H-guanosine by 5′-nuclease of snake venom. Add scintillation cocktail to observe the PDE isoenzymes activity. The selective inhibitor sildenafil of different concentrations were used to observe the inhibition of PDE5. Data replotted according to procedure of Dixon plots.ResultsThree PDE isoenzyme peaks were purificated from bovine corpus cavernosum. The PDE of the third peak had the strongest activity of cGMP hydrolyzation which could be inhibited by sildenafil apparently.ConclusionSince PDE5 was mainly found in corpus cavernosum tissue of mammalian, and sildenafil was a selective inhibitor of PDE5. It was suggested that the third peak was PDE5. The result was in agreement with the article reported.

关 键 词：磷酸二酯酶5活性 抑制作用 药理 

分 类 号：R977.3[医药卫生—药品] Q556[医药卫生—药学]