Chronic inflammation promotes proliferation in the prostatic stroma in rats with experimental autoimmune prostatitis: study for a novel method of inducing benign prostatic hyperplasia in a rat model

OBJECTIVE: Inflammation plays an important role in the development of benign prostatic hyperplasia (BPH). The aim of the present study was to reference the study of the pathological changes in the prostate gland of rats with experimental autoimmune prostatitis (EAP), for the development of experimental models of BPH. METHODS: Experimental autoimmune prostatitis was induced in rats by the intradermal injection of rat prostate antigen with immunoadjuvants. In case of the positive BPH group, BPH was induced by the subcutaneous injection of testosterone propionate. At the end of the 45-day model period, prostate weights were measured, and the histopathological analysis of the prostate glands was performed. The levels of cytokines, TGF-β1/RhoA/ROCK signals, and the oxidative stress status were also examined. RESULTS: Rats from the EAP group had a higher histological score than those from the control group. Compared to the samples from rats in the hormone-induced group, those from the EAP group showed a more pronounced increase in the size of the stromal compartment; this was characterized by the formation of reactive stroma and the deposition of a greater amount of extracellular matrix (ECM). Significant increases in the numbers of CD3-positive cells and CD68-positive cells, as well as a significant upregulation in the cytokine levels, and an increase in the TGF-β1 levels and activation of RhoA/ROCK signaling, were observed in the samples from rats in the EAP group. CONCLUSION: Chronic inflammation can induce BPH in rats via EAP model method. When performing drug experiments on the stroma compartments of BPH, the use of the EAP model is a recommendation of the authors based on this study.