Expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in human endometrium of unexplained infertility

Objective To study the expression of matrix metalloproteinase-9(MMP-9) and tissue inhibitor of metalloproteinase-1 protein(TIMP-1) in cycling endometrium with unexplained infertility and normal endometrium,and to explore the relationship between the expression of MMP-9,TIMP-1 in unexplained infertility and normal pregnancy.Methods Immunohistochemistry(S-P technique) was used to detect the expression of MMP-9 and TIMP-1 in endometrium of selected cases consisting of 30 unexplained infertility and 20 normal endometrium.Results The expression of MMP-9 and TIMP-1 in normal endometrium could be observed in glandular epithelium and stromal cells during different phase.They expressed low in proliferative phase,but obviously higher in secretory phase,which showed significant difference in statistics(P0.05).But in unexplained infertility their weak expression was noted during proliferative phase and secretory phase.Between the expression levels of infertility and normal endometrium,the difference was significant(P0.05).Conclusion The weak expression of MMP-9 and TIMP-1 will reduce the potential of endometrial acceptation and embryo implantation,and accordingly may bring about infertility.