Study On Morphology And Expression Of Integrin α4 And β1 In Mouse Endometrium During Preimplantation

Objectives①To observe the histology and ultrastructure changes in endometrium of normal and pregnant mouse during preimplantation.②To study the expression and distribution of integrinα4 andβ1 in mouse endometrium during preimplantation.③To approach the relation between morphology change and expression change of integrinα4 andβ1 in mouse endometrium during preimplantation. Methods Adult nulliparity Kunming mice were taken as study objects. For mating purposes, 3 females were housed overnight with 1 males. Females were checked by 7:00 A.M. the next morning, and the presence of a vaginal plug was designated as day 1 of pregnancy. 60 pregnant mice were randomly divided into 4 groups and every group comprised 15 mice. Mice were executed by luxatioing cervical vertebra and got their uterus on day 1,2,3 and 4 of pregnancy. Meanwhile, we got uterus from normal mice to contrast for:①Hematoxylin-Eosin (HE) staining was used to observe histologic structures in endometrium;②Ultrastructure changes in endometrium were observed by transmission electron microscope(TEM);③Immunohistochemical SP staining was used to measure the expression of integrinα4 andβ1 in mouse endometrium on day 1～4 of pregnancy;④Computer imaging system analyzed the results of immunohistochemical SP staining. Results①HE staining showed that normal mouse endometrium were make up of luminal epithelium and lamina propria.In lamina propria, it contained uterine glands, stroma cells, blood vessels and so on. The types of luminal epithelium and glandular epithelium were both simple columnar epithelium. On day 1～4 of pregnancy, structure changes of mouse endometrium appeared developmental tendency. It showed that amounts of uterine glands increased gradually, endometrium was physiological edema, intercellular space of stroma cells became augmented, and blood vessels accrementited.②Under TEM, cell organs in luminal epithelium, glandular epithelium and stroma cell in mouse endometrium on day 1～4 of pregnancy were more than normal mouse. Abundant Mi, RER, SG and so on in luminal epithelium and glandular epithelium and interstitial edema were observed on day 4 of pregnancy. Moreover, stroma cells got fat and round with affluent glycogen and lipid droplet intracytoplasm.③On day 1～4 of pregnancy, integrinα4 andβ1 were expressed more or less in luminal epithelium and glandular epithelium of uterus, and on day 4 of pregnancy the expression was strongest. On day 3 and 4 of pregnancy, integrinα4 andβ1 had positive expression in stroma cells. Conclusion①Secrete function in pregnant mouse endometrium was high during preimplantation and the changes were significant with the pregnant day increasing.②Integrinα4 andβ1 were expressed continuously in mouse endometrium on day 1～4 of pregnancy. On day 4 of pregnancy the expression was strongest.③On day 4 of pregnancy, the secrete function of luminal epithelium, glandular epithelium and stroma cell were highest during preimplantation. This phenomenon and the expression peak of integrinα4 andβ1 were at equal pace. It suggested that integrinα4 andβ1 may take part in the process of mouse embryo implantation.The expression intensity of integrinα4 andβ1 and the growth of endometrium during preimplantation were in-synchronism.