title: Effect of zinc deficiency and repletion on thymidine metabolism.
abstract: We studied the effect of zinc deficiency on thymidine metabolism in intact and wounded rats. Zinc deficiency was associated with significantly decreased incorporation of [methyl-3H] thymidine into skin DNA of both intact and wounded rats, as shown by liquid scintillation counting and autoradiography. With wounding, proliferation--as gauged by the labeling index--increased to about twice normal for zinc-supplemented rats, but 3.5-fold for zinc-deficient rats. However, despite the increased proliferation rate, wound-healing in deficient rats was always slower than in zinc-supplemented animals. Incorporation of 3H-labeled thymidine into spleen DNA at 2 and 4 h, and liver DNA at 4 h was also significantly less in zinc-deficient rats than in zinc-supplemented rats. Conversely, DNA synthesis was enhanced in the thymus gland of zinc-deficient rats. Further studies showed that significantly higher percentages of [methyl-14C] thymidine were oxidized by zinc-deficient rats. The specific involvement of the methyl group of thymidine was indicated by the observation of normal oxidattions of [2-14C] thymidine. These findings support the view that zinc directly regulates DNA synthesis.
mesh_terms: D000818:Animals; D004247:DNA / Q000096:biosynthesis; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012867:Skin / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013936:Thymidine / Q000378:metabolism*; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D004247:DNA; D015032:Zinc; D013936:Thymidine