title: Food restriction inhibits [3H] 7,12-dimethylbenz(a)anthracene binding to mouse skin DNA and tetradecanoylphorbol-13-acetate stimulation of epidermal [3H] thymidine incorporation.
abstract: It has been known for many years that reducing the food intake of laboratory mice and rats inhibits the development of a broad spectrum of chemically induced and spontaneous tumors, but the mechanism of this effect is poorly understood. Food restriction of A/J mice for two weeks is now shown to inhibit the binding of topically applied [3H]7,12-dimethylbenz(a)anthracene (DMBA) to skin DNA by 50% and to abolish the stimulation of [3H]-thymidine incorporation in the epidermis produced by topical application of the tumor promoter tetradecanoylphorbol-13-acetate (TPA). Similar effects on the actions of DMBA and TPA are observed following topical application of the adrenal steroid, dehydroepiandrosterone (DHEA), a potent glucose-6-phosphate dehydrogenase (G6PDH) inhibitor, while food restriction for two weeks depresses epidermal G6PDH activity by 60%. It is suggested that both the inhibition of [3H]DMBA binding to skin DNA and the TPA stimulation in epidermal [3H]thymidine incorporation result from a reduction in the NADPH cellular pool as a result of G6PDH inhibition.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000378:metabolism*; D000818:Animals; D004247:DNA / Q000378:metabolism*; D005508:Food Deprivation; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D012867:Skin / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism*
chemical_list: D015127:9,10-Dimethyl-1,2-benzanthracene; D004247:DNA; D013755:Tetradecanoylphorbol Acetate; D013936:Thymidine