Prostate extract with aluminum hydroxide injection as a novel animal model for chronic prostatitis/chronic pelvic pain syndrome.

OBJECTIVES

To establish a new animal model to mimic the clinical condition of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). CP/CPPS is a highly prevalent condition with detrimental effect on the quality of life, but the etiology, pathogenesis, and optimal treatment of CP/CPPS remain unknown. This new animal model would greatly contribute to the understanding and treatment of CP/CPPS.

METHODS

Forty Wistar rats were averagely and randomly divided into 5 groups (3 experimental groups, a normal control group, and a positive group) of 8 rats each. Experimental groups were subcutaneously injected with the mixture of prostate extract and aluminum hydroxide, the positive control group with prostate extract and complete Freund adjuvant (CFA), and the normal control group with 0.01 mol/L phosphate-buffered saline (0.01 M PBS). Hematoxylin and eosin stain and immunohistochemistry were respectively used to investigate the inflammatory lesion and the expression of tumor necrosis factor-alpha (TNF)-α in the prostate. In addition, the serum IgG was also evaluated. The t test was used to compare the statistical differences among groups.

RESULTS

Histopathological analyses indicated that prostate lesions in the group immunized with high concentrations of aluminum hydroxide in the presence of prostate extract 3 times was most severe, in addition there was also the highest expression of TNF-α and IgG in this group.

CONCLUSIONS

Prostate extract with aluminum hydroxide injection could successfully induce CP/CPPS in Wistar rats, which was in a dose-dependent and injection number-dependent fashion. This animal model might greatly benefit with further understanding of the etiology, pathogenesis, and optimal treatment of CP/CPPS.