Macrophages on intrauterine contraceptive devices produce prostaglandins

THE mechanisms whereby intrauterine contraceptive devices (IUDs) exert their anti-fertility effects remains unestablished¹. The involvement of prostaglandins (PGs) is being investigated^2-5, although alternative mechanisms have been proposed (for example, phagocytic and other actions of macrophages^6,7). Although the relative contributions of macrophages and PGs to the anti-fertility actions of IUDs remains uncertain, it is clear that introduction of the IUD into the endometrial cavity results in an infiltration by neutrophils and macrophages⁸ as well as increased PG levels in uterine venous blood in animals^9,10. While investigating the role of mediators of chronic inflammation we have demonstrated that the macrophage is a potent source of PGE¹¹, and since the macrophage is the predominant cell adhering to the IUD⁶ we have considered the possibility that such cells act as a source of PGs.