Effect of Polymorphonuclear Leukocytes on the Development of Mouse Embryos Cultured from the Two-Cell Stage to Blastocysts1

Abstract

The effect of polymorphonuclear leukocytes (PMNLs) on the development of pre-implantation mouse embryos cultured from the two-cell stage to blastocyst was investigated. PMNLs (1–2 × 10⁶) blocked development of most embryos beyond the four- or eight-cell stage. The embryotoxic activity declined with decreasing PMNL concentration. The activity of intact PMNLs or equal numbers of PMNLs that were homogenized or lyophilized following homogenization was similar. However, acidification of PMNL homogenates prior to lyophilization appeared to increase their activity, while homogenization of PMNLs under hypotonic conditions appeared to decrease their activity. The embryotoxic activity was not destroyed by storage of whole PMNLs for 1 week at 4 C.