Problem: Macrophages are highly individualized in tissues and their activities are a reflection of systemic and local environmental signals. The expression of activation (CD69, CD71) and adhesion (CD54) molecules on the surface of CD14+ endometrial macrophages at various phases of the menstrual cycle was compared with the cell surface receptors of peritoneal fluid macrophages.
Method of study: Two-colour-flow cytometry was used to determine the peritoneal and endometrial macrophage phenotype.
Results: Endometrium macrophages expressed a lower level of CD69+ and CD54+ macrophages than peritoneal macrophages. However, CD71 receptors displayed similar expression in both macrophage populations, endometrium and peritoneal, except during the proliferative phase.
Conclusion: These findings demonstrate the differences between macrophages from endometrium and peritoneal fluid with regard to CD69, CD71 and CD54 expression. In addition, increased numbers of endometrial macrophages in the late secretory phase of the menstrual cycle suggest that they may play a role in menstruation.