Lipid loading does not decrease inducibility of NF-κB but inhibits AP-1. Macrophages were cultured for 48 h in the presence of 5% LPDS ± 50 μg/mL ac-LDL. The cells were then stimulated with TNF (10 ng/mL) for 2 h. Nuclear extracts were prepared and transcription factor activities (lanes 1–5, NF-κB; lanes 6–10, AP-1) were determined in the extracts. The arrowheads indicate the positions of specific complexes. Lanes: 1 and 6, probe only; 2 and 7, control; 3 and 8, TNF; 4 and 9, ac-LDL; 5 and 10, ac-LDL + TNF. Similar results were obtained in five independent experiments.