Leukocyte Subpopulation Changes in Rats With Autotransplanted Endometrium and the Effect of Danazol

PROBLEM: This study examines immune cell populations in rats with autotransplanted endometrium and determines the effect of danazol on leukocyte subsets. METHODS: As an experimental model of endometriosis, an autologous endometrial segment was implanted in the rat peritoneum. We used flow cytometry to analyze lymphocyte subsets in the peripheral blood (PB) and peritoneal fluid (PF) of the following groups of rats: no treatment, sham operation, endometrial implantation, endometrial implantation treated with danazol, and normal rats treated with danazol. RESULTS: The natural killer (NK) cell population was decreased in both the PB and PF of rats with autotransplanted endometrium. Moreover, NK cells increased in a dose‐dependent manner following danazol administration. Surgery itself increased the number of peritoneal macrophages as compared with the untreated group. This elevation was suppressed partially by endometrium‐implantation and was attenuated by subsequent administration of danazol in a dose‐dependent fashion. CONCLUSIONS: These data suggest that ectopic endometrial cells may release immunosuppressive factors. This is the first documentation that rats with autotransplanted endometrium show the same immunologic changes as humans with endometriosis, and establishes the utility of this model for the study of endometriosis. 1995 Munksgaard