PURPOSE: We identify whether tachyphylaxis and @entity3327 effects of @entity7855 are related to regulation of phosphodiesterase-5 ( @entity7856 ) expression. MATERIALS AND METHODS: Cavernous smooth muscle cells (CSMCs) were isolated from young @entity35 and treated with 0, 1, 10 and 25 microM @entity7855 with or without 100 microM of @entity1854 for 3 and 7 days. The cells were subjected to reverse transcriptase-polymerase chain reaction and Western blot analysis for @entity7856 expression. Plasmid constructs carrying PDE-5A1 and @entity32040 promoters were transfected into COS-7 cells, treated with 25 microM @entity7855 and analyzed for promoter activities. To simulate @entity3327 , CSMCs were cultured under @entity519 or @entity519 and then analyzed for @entity7856 expression. Furthermore, @entity35 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 @entity7856 expression. RESULTS: Up-regulation of @entity7856 was noted in CSMCs treated with 25 microM @entity7855 for 7 days. @entity7856 messenger RNA and protein levels were significantly increased in the 7-day @entity7855 treated cultures. @entity1854 appeared to down-regulate @entity7856 expression. @entity7855 significantly increased the activities of PDE-5A1 promoter. @entity7856 expression was significantly reduced under @entity519 and @entity519 . The corpus cavernous tissue showed a gradual decrease in @entity7856 expression under @entity63 . CONCLUSIONS: Repeated treatment with @entity7855 at high concentrations was needed to simulate tachyphylaxis in our cell culture system. Adequate oxygenation was important for @entity7856 expression. Thus, sicklemic @entity1 may express @entity7856 at abnormally low levels, predisposing them at risk of stuttering @entity3327 .

Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity7856 :: ('8654', 'Gene') :: ['PDE-5'] @entity63 :: ('MESH:D007511', 'Disease') :: ['ischemia'] @entity1854 :: ('MESH:D009599', 'Chemical') :: ['sodium nitroprusside', 'Sodium nitroprusside'] @entity7855 :: ('MESH:C101426', 'Chemical') :: ['sildenafil', 'Sildenafil'] @entity3327 :: ('MESH:D011317', 'Disease') :: ['priapism'] @entity519 :: ('MESH:D000860', 'Disease') :: ['anoxia', 'hypoxia'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity32040 :: ('171115(Tax:10116)', 'Gene') :: ['PDE-5A2']
@entity3327 :: (MESH:D011317,Disease) :: ['priapism']
