EXPRESSION OF ALPHA-6 AND BETA-4 INTEGRIN SUBUNITS ON HUMAN ENDOMETRIUM THROUGHOUT THE MENSTRUAL-CYCLE AND DURING EARLY-PREGNANCY

Objective: To evaluate the expression of alpha 6 and beta 4 integrin s ubunits on surface and glandular endometrium throughout the menstrual cycle and during early pregnancy. Setting: Second Department of Obstet rics and Gynecology, University of Catania, Catania, Italy. Patient(s) : Thirty-two women. Nineteen of the women regularly menstruated in dif ferent phases of the cycle, and 13 were in the sixth to ninth week of gestation and required voluntary abortion. Intervention(s): Endometria l specimens collected during endometrial biopsy, hysterectomy, or volu ntary abortion. Main Outcome Measure(s): Immunohistochemical staining for alpha 6 and beta 4 integrin subunits in endometrial tissues. Resul t(s): Both subunits (poorly expressed in preimplantation days) reached a significant peak on the endometrial surface during the implantation window, which tended to disappear in the postimplantation phase. On g landular endometrium they exhibited an opposite trend, showing high le vels in the preimplantation and postimplantation days, whereas their e xpression decreased during the implantation window. The two subunits t ended to disappear in early pregnancy. Conclusion(s): alpha 6 and beta 4 integrin subunits are uniformly distributed and highly expressed on the endometrial surface during the implantation window; they decrease d dramatically in the postimplantation phase. These results could sugg est involvement of integrin-extracellular matrix components in blastoc yst-endometrium interaction during the early stages of implantation. ( C) 1998 by American Society for Reproductive Medicine.