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pubmed:abstractText |
Two polyacetates, aplysiatoxin and debromoaplysiatoxin, as well as 12-O-tetradecanoylphorbol-13-acetate (TPA), mezerein and teleocidin enhance nitroblue tetrazolium (NBT) reduction in mouse peritoneal macrophages in vitro. The ED50 values for NBT reduction of these 5 TPA-type tumor promoters were 4.2 ng/ml for TPA, 36 ng/ml for mezerein, 0.53 ng/ml for teleocidin, 1.5 ng/ml for aplysiatoxin and 108 ng/ml for debromoaplysiatoxin. The NBT reduction induced by the 5 tumor promoters is inhibited by 2 inhibitors of tumor promotion, retinoic acid and dibromoacetophenone. The possibility that tumor promotion by TPA-type tumor promoters involves similar mechanisms such as superoxide anion radicals release in cell membranes is discussed.
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