Investigating endometriosis development and endometriosis-related pain over time and in relation to estrogen in a laparoscopic mouse model

Abstract

BackgroundEndometriosis is a complex disease, and its pathophysiology is still unclear. Therefore, endometriosis animal models need to be carefully selected and examined to be useful for identification of novel therapies for women with endometriosis. In this study, we evaluated endometriosis-associated pain, and time- and estrogen-related development of endometriotic lesions after laparoscopic implantation of menstrual endometrium in a homologous mouse model for endometriosis. MethodsEndometriosis was induced by laparoscopic introduction of 10 menstrual endometrial tissue pieces into the peritoneum of ovariectomized recipient mice (59 estrogen-substituted; 59 estrogen-depleted). Sham animals (57 estrogen-substituted; 60 estrogen-depleted) received 10 pieces of perigonadal adipose tissue. The animals were sacrificed at 1, 2, 3, 4, 6 or 8 weeks after induction, the attached peritoneal implants localized and excised and immunohistochemically analyzed. Additionally, endometriosis-related pain was evaluated by measuring mechanical allodynia, thermal hyperalgesia, locomotor activity and anxiety-like behavior before and after tissue implantation. ResultsAt least one implant per mouse could be retrieved in 94% (111/118) of the endometrial tissue animals and in 78% (91/117) of the adipose tissue animals (p View larger version (39K): org.highwire.dtl.DTLVardef@119ad34org.highwire.dtl.DTLVardef@ba5b8borg.highwire.dtl.DTLVardef@d020ccorg.highwire.dtl.DTLVardef@1941e8_HPS_FORMAT_FIGEXP M_FIG C_FIG