['To evaluate the activities of acetyl coenzyme A (AcCoA):arylamine N-acetyltransferase (NAT) of intact cumulus granulosa cells and the role of leukemia inhibitory factor (LIF) upon their NAT activities.', 'Thirty women accepted controlled ovarian hyperstimulation (COH) and oocyte retrievals. Human cumulus granulosa cells were obtained during oocyte retrievals. Using 2-aminofluorene (2-AF) and p-aminobenzoic acid (PABA) as substrates, NAT activity of all samples was determined by high pressure liquid chromatography. After the incubation with different time and concentrations of 2-AF, PABA, and LIF, 2-acetyl-aminofluorene (2-AAF) and N-acetyl-PABA (N-Ac-PABA) were measured.', 'After incubation with 2.812, 5.625, 11.25, and 22.5 microM of 2-AF/PABA, their product concentrations (2-AAF/N-Ac-PABA) were 0.42/0.32, 0.76/0.58, 1.29/1.04, and 1.94/1.26 nmol/10(6) cells, respectively. After 6, 12, 18, and 24 h incubation with 11.25 microM of 2-AF/PABA, their product concentrations were 0.19/0.12, 0.56/0.4, 0.98/0.79, and 1.3/1.0 nmol/10(6) cells, respectively. After incubation with 0, 5, and 50 microM of LIF, the 2-AAF/N-Ac-PABA concentrations were 0.98/0.80, 0.70/0.52, and 0.49/0.30 nmol/10(6) cells, respectively.'] Does leukemia inhibitory factor decrease the arylamine N-acetyltransferase activity in human cumulus granulosa cells?