Pathological evaluation of the rat endometriosis model.

OBJECTIVE

To observe in detail the morphology of experimental rat endometriosis, specifically in peritoneum adjacent to uterine transplants attached via autotransplantation.

DESIGN

Light and electron microscopic study.

SETTING

Tochigi Institute of Clinical Pathology, Japan.

ANIMAL(S): Female-SD rats maintained on a schedule of 12 hours of light and 12 hours of dark for 2 weeks.

INTERVENTION(S): Uterine transplants were attached to rat peritoneum via the surgical autotransplantation technique. The implanted area of peritoneum, including abdominal muscle, were excised from anesthetized rats at four (n = 10), seven (n = 10), and 14 (n = 10) days after uterine autotransplantation. The mesenteries were autotransplanted as a comparative control.

MAIN OUTCOME MEASURE(S): We examined the morphologic alterations of uterus-attached peritoneum following the time interval after the implantation.

RESULT(S): In rat endometriosis models, the stromal tissue of uterus-attached peritoneum showed proliferation and infiltration of mast cells, eosinophils, plasma cells, lymphocytes, and macrophages. These lesions increased with time after implantation; however, ultimately these infiltrating cells disappeared and proliferation declined.

CONCLUSION(S): Our findings suggest that uterine autotransplantation induces the infiltration of allergic inflammatory-related cells and proliferative lesions in peritoneal stroma attached endometrium. These data should prove useful for investigations of human endometriosis.