To investigate the role of macrophageinflammatory protein (MIP)-3αin human ovulation. Study of the levels of MIP-3αin serum and follicular fluid. The effects of interleukin (IL)-1α, IL-1 receptor antagonist (RA), and tumor necrosis factor (TNF)-αon the secretion of MIP-3αby primary cultured granulosalutein cells and an immortalized granulosa cell line (GC1a) were investigated. Research laboratory at a university medical school. Fortysix patients with sterility undergoing in vitro fertilization and embryo transfer (IVFET).Follicular fluid was obtained from study participants, and granulosalutein cells and GC1a were incubated with IL-1α, IL-1RA, or TNF-αfor 4 to 32 hours. The concentration of MIP-3αin human follicular fluid was measured and correlated with oocyte maturation. We also cultured granulosa cells and examined the regulation of MIP-3αproduction. The concentrations of MIP-3αin the serum, follicular fluid, and culture medium were measured using enzymelinked immunoabsorbent assay. Concentrations of MIP-3αwere significantly higher in the follicular fluid, but it was not detected in the serum. Concentrations of MIP-3αwere statistically significantly higher in the follicular fluid containing mature oocytes than in follicular fluid containing immature oocytes. The production of MIP-3αwas markedly increased over the basal level after treatment with IL-1αand TNF-αin a dosedependent manner. The stimulatory effect of IL-1αwas inhibited by IL-1RA. Our data suggest that MIP-3αwas present in follicular fluid and correlated with oocyte maturation, and was regulated by IL-1αand TNF-α. Thus, MIP-3αmay play an important role in the human preovulatory process. To investigate the role of macrophageinflammatory protein (MIP) -3αin human ovulation. Study of the levels of MIP-3αin serum and follicular fluid. The effects of interleukin (IL) -1α, IL- factor (TNF) -αon the secretion of MIP-3αby primary cultured granulosalutein cells and an immortalized granulosa cell line (GC1a) were investigated. Research laboratory at a university medical school. Fortysix patients with sterility undergoing in vitro fertilization and embryo transfer (IVFET) .Follicular fluid was obtained from study participants, and granulosalutein cells and GC1a were incubated with IL-1α, IL-1RA, or TNF-αfor 4 to 32 hours. The concentration of MIP-3αin human follicular We also cultured granulosa cells and examined the regulation of MIP-3α production. The concentrations of MIP-3αin the serum, follicular fluid, and culture medium were measured using enzyme -link Concentrations of MIP-3αwere significantly in the follicular fluid, but it was not detected in the serum. Concentrations of MIP-3αwere statistically significant higher in the follicular fluid containing mature oocytes than in follicular fluid containing immature oocytes. The production of MIP-3αwas markedly increased over the basal level after treatment with IL-1αand TNF-αin a dose-dependent manner. The stimulatory effect of IL-1αwas inhibited by IL-1RA. Our data suggest that MIP-3αwas present in follicular fluid and correlated with oocyte maturation, and was regulated by IL-1α and TNF-α. Thus, MIP-3αmay play an important role in the human preovulatory process.