The rat model of endometriosis-related pain is established by surgically transplanting endometrial tissue onto the sciatic nerve of rats. When the ectopic lesions are located around the sciatic nerve root or directly invade the peripheral sciatic nerve, they can induce nerve irritation. Due to the ectopic implantation, the lesions also trigger massive leukocyte infiltration around the sciatic nerve, leading to inflammatory responses and sciatica. This model is widely used for evaluating the efficacy of analgesic drugs for endometriosis. Notably, the pain in this model is associated with the estrous cycle.

**SD rats (female, 8 weeks old)**

**Modeling method**:
Uterine horn tissue was excised and sutured onto the sciatic nerve. The endometriosis pain model was successfully established 7 days after surgery.

**Evaluation index**:
Measurement of mechanical pain threshold

Mechanical withdrawal threshold (MWT)