Fig. 5

Urethral tissue histological staining. Control group: Hematoxylin and eosin (HE) staining shows that the urethral epithelium is composed of three layers of cells, with a clear urethral lumen and intact epithelium, submucosa, muscular layer, and vascular sinus. Picrosirius Red staining shows well-arranged muscle fibers. TIP group: HE staining shows intact urethral epithelium composed of 4 – 7 layers of epithelial cells. At the dorsal incision site, the submucosa is absent, and there is a lack of longitudinal muscle fibers and vascular sinus. Picrosirius Red staining shows inflammatory cell infiltration in the sutured area, with disordered muscle fiber arrangement and mild congestion.