LAUSR

taken mice bladder tissue was performed by Q-PCR, immunostaining methods. Data are presented as mean S.E. P value< 0.05 (*),< 0.01 (**) was considered to indicate statistical significance by student t-test. RESULTS: In micturition reflex, the number of urination per day significantly increased (13.5 1.4 times vs. 7.5 0.5 times; P < 0.001, N [ 5) in BOO compared to sham. The daily urination volume and voiding volume were significantly decreased in BOO compared to sham (1.1 0.1 ml vs. 1.9 0.2 ml, 123.9 3.2 ml vs. 324.3 4.0 ml; P < 0.01, N [ 5, respectively). In cystometry, BOO mice's non-voiding contractions were significantly increased. In BOO, mRNA expression of c-kit, CD34 and PDGFRa was significantly elevated, however interestingly immunostaining indicated not only significant reduction of PDGFRaþ cells (9.5 0.7 % vs. 14.5 0.7 %; P < 0.01, N [ 4) but also double positive (CD34þ and PDGFRaþ) cells were dominantly expressed in serosa side but not interstitial layer in BOO model. CONCLUSIONS: BOO model mice are firstly established as overactive bladder using metal rings obviously resulting from the significant differences in voluntarily voiding behavior and various parameters from cystometry. BOO model reduced PDGFRaþ cells despite of its mRNA expression increase. This study revolutionarily demonstrated that double positive (CD34þ and PDGFRaþ) cells (presumably pace maker cells) in urinary bladder were increased in serosa side but not interstitial layer in BOO model.