Endostatin inhibits the growth of endometriotic lesions but does not affect fertility.

OBJECTIVE: To determine whether endometriosis can be treated with the angiogenesis inhibitor endostatin and the effect of this treatment on fertility and reproduction.
DESIGN: Pharmacologic intervention in a surgically induced model of endometriosis and in female mice undergoing mating.
SETTING: Animal research facility. ANIMAL(S): Eight-week-old, female C57BL/6 and SCID mice. INTERVENTION(S): After implantation of autologous endometrium, mice received endostatin or the vehicle-matched control for 4 weeks. For the reproductive function study, mice receiving endostatin or vehicle were mated and reproductive functions were observed. MAIN OUTCOME MEASURE(S): Growth of endometriotic lesions after 4 weeks of treatment; estrous cycling, corpus luteum formation, serum hormone levels, and mating time as fertility measures; and pregnancy rates, length of pregnancy, fetal vitality, number, and outcome of litter as reproductive measures. RESULT(S): Endostatin suppressed the growth of endometriotic lesions by 47% compared with controls. Estrous cycling and corpus luteum formation were normal in both groups. Female mice receiving endostatin were as fertile as mice receiving vehicle, had normal pregnancies, and delivered the same number of pups. The offspring were healthy without teratogenic stigmata and reproduced normally themselves. CONCLUSION(S): Antiangiogenic therapy with endostatin may present a promising novel, nontoxic therapeutic option for patients with endometriosis.