Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and priapism
Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and priapism
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DOI：
10.1097/01.ju.0000075500.11519.e8
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发表时间：
2003-08-01
影响因子：
6.6
通讯作者：
Lin, CS
中科院分区：
文献类型：
--
作者：
Lin, GT;Xin, ZC;Lin, CS
目的：我们确定西地那非的快速耐受和阴茎异常勃起作用是否与磷酸二酯酶 5 (PDE-5) 表达的调节有关。材料和方法：从幼鼠中分离海绵体平滑肌细胞 (CSMC)，并用 0、1、10 和 25 μM 西地那非（含或不含 100 μM 硝普钠）处理 3 和 7 天。对细胞进行逆转录酶-聚合酶链式反应和蛋白质印迹分析以检测 PDE-5 的表达。将携带PDE-5A1和PDE-5A2启动子的质粒构建体转染至COS-7细胞中，用25μM西地那非处理并分析启动子活性。为了模拟阴茎异常勃起，在缺氧或缺氧条件下培养 CSMC，然后分析 PDE-5 表达。此外，对大鼠进行双侧阴部动脉结扎1天至14周，并对海绵体组织进行逆转录聚合酶链式反应分析PDE-5的表达。结果：用25μM西地那非处理7天的CSMCs中发现PDE-5的上调。在西地那非处理 7 天的培养物中，PDE-5 信使 RNA 和蛋白质水平显着增加。硝普钠似乎可以下调 PDE-5 的表达。西地那非显着增加 PDE-5A1 启动子的活性。缺氧和低氧条件下PDE-5表达显着降低。缺血条件下海绵体组织中PDE-5的表达逐渐降低。结论：需要用高浓度西地那非重复治疗来模拟我们的细胞培养系统中的快速耐受。充足的氧合对于 PDE-5 的表达很重要。因此，镰状细胞病患者的 PDE-5 表达水平可能异常低，使他们面临断续性阴茎异常勃起的风险。
Purpose: We identify whether tachyphylaxis and priapism effects of sildenafil are related to regulation of phosphodiesterase-5 (PDE-5) expression.Materials and Methods: Cavernous smooth muscle cells (CSMCs) were isolated from young rats and treated with 0, 1, 10 and 25 muM sildenafil with or without 100 muM of sodium nitroprusside for 3 and 7 days. The cells were subjected to reverse transcriptase-polymerase chain reaction and Western blot analysis for PDE-5 expression. Plasmid constructs carrying PDE-5A1 and PDE-5A2 promoters were transfected into COS-7 cells, treated with 25 muM sildenafil and analyzed for promoter activities. To simulate priapism, CSMCs were cultured under anoxia or hypoxia and then analyzed for PDE-5 expression. Furthermore, rats underwent bilateral pudendal arterial ligation for 1 day to 14 weeks, and corpus cavernous tissues were subjected to reverse transcriptase-polymerase chain reaction analysis for PDE-5 expression.Results: Up-regulation of PDE-5 was noted in CSMCs treated with 25 muM sildenafil for 7 days. PDE-5 messenger RNA and protein levels were significantly increased in the 7-day sildenafil treated cultures. Sodium nitroprusside appeared to down-regulate PDE-5 expression. Sildenafil significantly increased the activities of PDE-5A1 promoter. PDE-5 expression was significantly reduced under anoxia and hypoxia. The corpus cavernous tissue showed a gradual decrease in PDE-5 expression under ischemia.Conclusions: Repeated treatment with sildenafil at high concentrations was needed to simulate tachyphylaxis in our cell culture system. Adequate oxygenation was important for PDE-5 expression. Thus, sicklemic patients may express PDE-5 at abnormally low levels, predisposing them at risk of stuttering priapism.