In the SUI model where vaginal dilation simulates birth trauma, vaginal dilation induces dysfunction of urethral smooth muscle cells, impairs their contractility, and ultimately weakens urethral contractile function, leading to urinary incontinence. Animals with gonadectomy are more prone to urinary incontinence compared with normal animals, especially in females, where the risk of urinary incontinence is significantly higher after ovariectomy.

- **Animals**: Female SD rats, 6–8 weeks old
- **Model establishment**: After ovariectomy, a urinary catheter was inserted into the urethra. Appropriate pressure was applied to the catheter and maintained for 4 hours to successfully establish a stress urinary incontinence model.
- **Evaluation index**: HE staining

HE staining (pubococcygeus muscle, sphincter)