Effect of interleukin-1 on gamete interaction and mouse embryo development.
 Early stages of endometriosis have been shown to be associated with infertility.
 The pathophysiology of this relationship is unclear.
 To determine if interleukin-1 (IL-1), a peritoneal macrophage product, has any effect on gamete interaction and early embryo development, human recombinant IL-1 was added to the coincubation of gametes in the sperm penetration assay (SPA), human zona pellucida assay (ZPPA) and culture medium (Ham's F-10) used for processing semen samples with the layering method, with analysis of velocity and motility after 24 hours.
 IL-1 was also added to mouse embryos (two cells) cultured for 72 hours.
 The results showed that IL-1 caused impairment of SPA and ZPPA when compared to control medium, without significant alterations in sperm velocity and motility.
 Also, IL-1 demonstrated significant inhibition of mouse embryo development.
 These results help explain subfertility associated with early stages of endometriosis.
