OBJECTIVETo investigate the pathogenesis of chronic prostatitis / chronic pelvic pain syndrome (CP / CPPS) by constructing the rat model of intraprostatic urinary reflux associated prostatitis caused by partial urethral obstruction.

METHODSFifty-four SD male rats were divided into an experiment group (n = 30) and a partial urethral obstruction (PUO) sham operation group (n = 24). Shinsuke Takechi's surgical method was adopted to achieve PUO and induce intraprostatic urinary reflux in the experiment group. While in the sham operation control group, the prostates were harvested at 1, 3 and 7 days after release from 3-day PUO, their morphological changes observed with the light microscope and the expression of cyclooxygenase-2 (COX-2) examined by immunohistochemistry.

RESULTSInflammation was observed in the prostate of the experiment group at 1, 3 and 7 days after release from PUO and alleviated with the passing of time, while the control group remained normal. The expression of COX-2 in the prostate was significantly higher in the experiment group than in the control (P < 0.05) and the staining of COX-2 became stronger with the lapse of time (P < 0.05).

CONCLUSIONAn animal model of intraprostatic urinary reflux associated prostatitis was constructed. The up-regulated expression of COX-2 induced by intraprostatic urinary reflux may be closely related with the development of CP / CPPS.