Establishment of an ICR Mouse Model of Adenomyosis by Oral Administration of Tamoxifen

Objective To establish an ICR mouse model of adenomyosis with tamoxifen and to characterize the adenomyosis nodules,estrus,angiogenesis and uterine inflammation in this animal model.Methods ICR mice with adenomyosis were induced by orally administration of tamoxifen on days 2～5 after birth.15 drug and 15 control mice were killed on day 42,day 85～95 and day 135～145,respectively.Hematoxylin and eosin(HE) staining was performed to examine the adenomyosis nodules.Estrous cycle was determined by the presence of a characteristic vaginal discharge.Microvessel density,diameter and the ratio of area in the uterus were assessed by immunohistochemistrial staining with CD31.The gene expression of bradykinin receptor-1(BKR-1) and neurokinin1 receptor(NK1-R) was detected by RT-PCR.Results All mice dosed with tamoxifen developed adenomyosis with an incidence rate of 100%.The microvessel density and the ratio of area in myometrium of experimental mice were significantly higher than those in the controls(P0.05).In the uterus of 135～145 d drug mice,the mRNA expression of BKR-1 and NK1-R was significantly higher than that of controls(P0.05).Conclusion The mouse model of adenomyosis induced by tamoxifen has abnormal angiogenesis,inflammation and pain related receptor expression in the uterus.Moreover,it is simple and effective to create this model,valuable for future adenomyosis research.