Experimental Study On The Expression Of The Receptors Of DBA,ECL And RCA-Ⅰ In Mouse Endometrium During Implantation

Objectives: Blastocyst implantation is a complicated biological phenomenon involving the recognition ,adhesion and acception between blastocyst and endometrium and is the key of pregnancy During implantation,the endometrium has the highest receptivity to the blastocyst .Many factors have been found play roles in this process, including hormones, cytokines, and adhesion molecules .Among them, lectin receptors are catching more and more eyes.Lectin receptors ,which can combine with specific lectins are glycoproteins or glycolipids located on the cell surface . More and more experiments have proved that lectin receptors participate the process of fertilization , blastocyst implantation and differentiation of embryo .To explore the relationship between implantation and the lectin receptors distributed in the endometrium ,we used early pregnant mice as the model system to examine the normal distribution and dynamic changing of lectin receptors in endometrium with affinity cytochemistry and image analysis. Thus ,we could determine which kinds of lectin receptors are indispensable for implantation ,thereby could enrich the theory about implantation and provide experimental evidence for new anti-implantation methods. Methods:The mature female mice were operated with tubal ligation of one side of the oviduct..Two weeks later ,the mice were mated with mature male mice. The pregnant mice were killed on day 4,6,7,8,9 of pregnancy by neck dislocation .the uteri were excised(the unpregnant side as controls ),then fixed with 4% paraformaldehyde ,then dehydrated ,embedded in wax, finally the specimens were sliced into section of 6um in thickness .The distribution of ECL,DBA,RCA-I receptors on the specimens were examined with affinity cytochemistry and image analysis. Results:1 DBA: On the pregnant side ,DBA receptor is mainly expressed in trophoblast and its basement membrane and the basement of blood vessels..On the unpregnant side ,however,is mainly in the basement membarane of the blood vessels. On both sides,the expression of the receptor present a trend of first increasing and then decreasing .The expression peak of both sides appears on day 7 and that on pregnant side is higher than that on unpregnant side.2 ECL:On the pregnant side,ECL receptor is mainly distributed in trophoblast and its basement membrane, the surface of the decidual cells and their surrounding extracellular matrix(ECM) ,The staining intensity in SDZ is higher than that in PDZ and in antimesome side is higher than in mosometrial side. .On unpregnant side ,the ECL receptors are mainly expressed on superficial surface of endometrial epithelium and uterine gland epithelium. The expression of ECL also present a trend of first increasing and then decreasing. The expressing peak of ECL receptor on both sides appears on day 6. The expressing intensity of ECL receptor on pregnant group is higher than that on unpregnant side from day 4 to day 9.3 RCA- I :The results show that RCA- I receptors and ECL receptors have a similar expressing pattern on both pregnant and unpregnant sides. On the pregnant side, RCA-I receptor is mainly distributed in trophoblast and its basement membrane ,the surface of the decidual cells and their surrounding extracellular matrix(ECM) ,the staining intensity in SDZ is higher than that in PDZ and in antimesometrial side is higher than in mosometrial side. .On unpregnant side ,the RCA-I receptors are mainly expressed on superficial surface of endometrial epithelium and uterine gland epithelium .The expressing peak of RCA- I receptor on both sides appears on day 6. The expressing intensity of the receptor on pregnant side is higher than that in unpregnant sidefrom day 4 to day 9. Conclusions:1, The receptors of DBA,ECL and RCA-I play important role in the process of blastocyst implantation in mouse.They may regulate the recognization and adhesion between blastocyst and endometrium and implantation.2, The distribution of these lectin receptors express on pregnant side are different from that on unpregnant side in one pregnant mouse.3,The distribution and expressing intensity of different lectin receptors are different.4, The stimulus of blastocyst to endomotrium is not a necessary condition for the expression of the receptors of these lectins,but the direct stimulating of blastocyst can change the level of expression.Significance:The results of pregnant study prove that ,in the process of implantation ,the distribution and expressing intensity of those lectin receptors in endometrium endure changes .This can ensure blastocyst to implant in the endometrium and to develop further.These changes are caused not only by hormones from mother body ,but also by the stimulative sigals derived from blastocyst .We use the pregnant mice as model system,which have been operated with tubal ligation of one side of oviduct. The unpregnant side of the uterus was taken for control of the pregnant side of the same uterus .This method could prevent the influence of differences ,for example ,the difference of hormone levels in different individuals. .Future study is needed to find out the molecular mechanism of how the embryonic signals cause the changes of the lectin receptors and how the receptors regulate the implantation.