Heterologous transplantation of activated murine peritoneal macrophages inhibits gamete interaction in vivo: a paradigm for endometriosis-associated subfertility.
 Macrophage hyperactivation has been postulated to be the pathologic aberration in patients suffering from endometriosis-associated subfertility.
 In this report an in vivo model for macrophage-mediated infertility is described.
 Populations of macrophages were obtained from an inbred strain of mice (Balb/C) as follows: (1) in vivo hyperactivated macrophages (harvested from donor mice treated with intraperitoneal thioglycolate); (2) hyperactivated macrophages deactivated ex vivo with the protein synthesis inhibitor emetine; and (3) basal state (nonactivated) macrophages obtained from untreated mice.
 Recipient mice underwent ovarian hyperstimulation with pregnant mare serum gonadotropins; 2 x 10(6) macrophages were transferred on the afternoon of stimulation day 3 before injection of human chorionic gonadotropin (hCG) and mating.
 Unfertilized oocytes and 4-cell embryos were counted on day hCG +2 as a reflection of reproductive performance.
 Heterologous transfer of in vivo hyperactivated macrophages, but not basal state macrophages, significantly inhibited fertilization.
 This effect was largely reversed by pretreatment with emetine.
 These experiments confirm the relevance of macrophage-mediated interference with early reproductive performance and provide a model for the development of alternative therapies (e.g., immunomodulation of the peritoneal fluid environment) for endometriosis-associated subfertility.
