Local surgical trauma in the penile tunica albuginea of the rat: a new animal model of Peyronie's disease.

BACKGROUND: Peyronie's disease (PD) is a relatively common clinical disorder of the penis that causes curvature and erectile dysfunction. However, the pathophysiological processes of PD are not well understood in current animal models and there exists limited clinical treatment options, which significantly impedes translational research. AIM: This study aimed to develop a novel rat model of PD induced by local surgical tunica albuginea trauma and compare it with the TGF-β-induced model to elucidate the scientific soundness and feasibility of the local surgical tunica albuginea trauma-induced PD model. METHODS: A total of 24 male standard deviation rats were randomly allocated into three groups: sham group, surgical trauma group, and TGF-β group. The sham group received a skin incision only, whereas the surgical trauma group and the TGF-β group underwent PD model establishment via microsurgical tunica albuginea trauma and TGF-β injection, respectively. Six weeks post-modeling, penile blood perfusion, degree of curvature and erectile function were quantified. Penile tissues were subsequently harvested for histological analysis and Western blotting was used to evaluate tunica albuginea fibrosis. OUTCOMES: PD model of surgical tunica albuginea trauma was successfully established and exhibited more pronounced fibrotic phenotypes in the penile tunica albuginea. RESULTS: Compared with TGF-β-induced models, laser speckle imaging revealed significantly reduced penile blood perfusion in surgical trauma group, accompanied by more severe penile curvature with corresponding angular and curvature alterations. HE and Masson's trichrome staining demonstrated marked local thickening and significantly increased collagen deposition in the penile tunica albuginea of rats in the surgical trauma group. Sirius red staining revealed a marked increase in collagen I and collagen III content. Immunofluorescence staining and Western blot analysis revealed that the surgical trauma group exhibited more pronounced alterations in the expression levels of fibrosis-related markers (Fibronectin, α-SMA, Collagen I, and Collagen III) in penile tissue. CLINICAL IMPLICATIONS: The rat model of tunica albuginea surgical trauma provides a promising option for preclinical PD research. STRENGTHS AND LIMITATIONS: The tunica albuginea surgical trauma-induced PD model established in our study has been scientifically validated. However, the precise pathogenesis of the model requires further investigation. CONCLUSION: The tunica albuginea surgical trauma-induced PD model was successfully established and demonstrates a more pronounced fibrotic phenotype in the penile tunica albuginea, potentially better recapitulating the pathophysiological processes of PD.