Inhibition of 12-O-tetradecanoylphorbol-13-acetate-induced nitroblue tetrazolium reduction in mouse peritoneal macrophages by various tumor promotion inhibitors

Abstract The effects of various inhibitors on 12- O -tetradecanoylphorbol-13-acetate (TPA)-induced reduction of nitroblue tetrazolium (NBT) in mouse peritoneal macrophages were investigated. The reduction was inhibited by phospholipase A 2 inhibitors, such as dibromoacetophenone, the lipoxygenase inhibitor nordihydroguaiaretic acid, an NADH-dehydrogenase inhibitor, the microfilament inhibitor cytochalasin B, oxygen radical scavengers such as superoxide dismutase, antioxidants such as butyl hydroxyanisole and non-specific inhibitors such as retinoic acid. The reduction was not affected by the cyclooxygenase inhibitor indomethacin or the H 2 O 2 scavenger catalase.