Abstract
<title>Abstract</title> <p> <bold>Background:</bold> Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common and refractory disease in urology, with a complex pathogenesis involving inflammation, neural dysregulation, and microcirculatory disorders. Recent evidence highlights tissue hypoxia as a key pathophysiological mechanism. Hypoxia-inducible factor-1α (HIF-1α) stabilizes under hypoxic conditions and activates downstream genes related to inflammation and fibrosis, forming a “hypoxia-inflammation” vicious cycle. However, existing animal models (e.g., bacterial infection, hormone-induced, autoimmune models) primarily induce inflammation as a cause rather than a consequence of hypoxia, making it difficult to study hypoxia as an initial driver. Physical hypoxic chambers induce systemic hypoxia and are costly. Therefore, a model that directly and specifically induces localized prostatic hypoxia is urgently needed. In this study, we innovatively establish a novel rat model of prostatitis driven by hypoxia using cobalt chloride (CoCl₂) chemical induction, with a “local priming + systemic amplification” strategy. This technical report aims to describe and validate this model. <bold>Methods:</bold> Male Sprague-Dawley rats (250–350g) were randomly divided into sham and model groups (n=6/group). On Day 0, rats in the model group received multi-point intraprostatic capsule injection of CoCl₂ (5 mg/kg, 100 μL per point) under anesthesia, while sham rats received equal volume of saline. On Days 1 and 2, model rats received intraperitoneal injections of CoCl₂ (10 mg/kg) for systemic amplification. On Day 3, prostate tissues were collected. Model validation included: (1) Hematoxylin-eosin (HE) staining for histopathological changes; (2) Western blot for HIF-1α protein expression; (3) ELISA for pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). Data were analyzed by unpaired Student’s t-test (P < 0.05 considered significant). <bold>Results:</bold> Compared with the sham-operated group, the model group exhibited marked histopathological changes in the prostate, including hydropic degeneration, necrosis and shedding of epithelial cells, and extensive inflammatory cell infiltration, with a significantly elevated inflammation score (*p* < 0.05). Both immunohistochemistry and Western blot analyses revealed a significant upregulation of hypoxia‑inducible factor‑1α (HIF-1α) protein expression in the model group (*p* < 0.05). Western blot also showed increased cleaved caspase-1 levels, indicating inflammasome activation. ELISA demonstrated that the concentrations of pro‑inflammatory cytokines IL-1β, IL-6, and TNF-α in prostate tissues were significantly higher in the model group than in the sham group (*p* < 0.05). Collectively, these results confirm that combined intraperitoneal and intraprostatic injection of cobalt chloride successfully establishes a rat model of prostate hypoxia and inflammation. <bold>Conclusion:</bold> Local injection of cobalt chloride can construct hypoxic inflammation model of rat prostate, which has the advantages of targeting, minimally invasive and simple, and provides a reliable platform for the study of prostate disease mechanism and drugs. </p>