Bladder function in 17β-estradiol-induced nonbacterial prostatitis model in Wister rat, "Beyond the Abstract," by Seiji Matusmoto, MD, PhD

BERKELEY, CA (UroToday.com) - Chronic inflammation in the prostate, known as chronic prostatitis (CP), has recently been recognized as an important component of the symptom progression of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Men with symptoms of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), NIH Category III, often have voiding complaints. Other previous studies showed that the voiding symptoms do not correlate with urodynamic findings, but a significant proportion of patients treated for CP/CPPS may have bladder outlet obstruction (BOO) or bladder dysfunction. Numerous mechanistic explanations have been proposed for the association of human voiding dysfunction with CP/CPPS, but the sequential relationship between prostatic inflammation and voiding dysfunction remains unclear. In the present study, we investigated bladder function in a model of nonbacterial prostatic inflammation induced by castrated rats with 17β estradiol.

Ten-month-old male Wistar rats were divided into 2 groups, sham and NBP (both N=8). NBP was induced by castration followed by daily subcutaneous injection of 17β-estradiol for 30 days. On the 31st day after surgery, we investigated

(1) voiding behavior,

(2) bladder blood flow,

(3) prostate and bladder weight, and proinflammatory cytokines (TNF-α and CXCL1) levels, and

(4) bladder contractile responses to electrical field stimulation (EFS), carbachol, and KCl.

In results:

(1) voiding behavior (average micturition volume, total urine volume and number of micturitions), and

(2) bladder blood flow were not significantly different between the sham and NBP groups.

(3) NBP led to a significant decrease in prostatic weight and increase in proinflammatory cytokine levels in the prostate, but NBP did not cause a significant change in bladder weight or proinflammatory cytokine levels in the bladder, and

(4) bladder contractile forces in response to EFS, carbachol and KCl were not significantly affected by NBP.

In conclusion, in a 17β-estradiol-induced model of nonbacterial prostatitis in castrated Wistar rats, prostatic weight decreased and prostate proinflammatory cytokines increased; bladder function was not affected. Rat prostatitis models generally differ in the type and extent of lower urinary tract dysfunction depending on the cause and severity of prostatitis. Our results were limited by the fact that this model is suitable for investigating inflammatory aspects of CP/CPPS.

Written by:
Seiji Matusmoto, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

Asahikawa Medical University
Renal and Urological Surgery
2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510, Japan

Bladder function in 17β-estradiol-induced nonbacterial prostatitis model in Wister rat - Abstract

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