Baker G W, Duncan J R
J Natl Cancer Inst. 1983 Feb;70(2):333-6.
The effect of zinc on the growth of a transplantable DAB hepatoma in young male Wistar rats was determined. Both a zinc deficiency (less than 0.5 microgram/g feed) as well as high levels of dietary zinc (500 micrograms/g feed) significantly reduced tumor growth. Both high- and low-zinc diets resulted in reduced activity of the salvage pathway of thymidine synthesis as well as reduced 32PO4 incorporation into DNA and diminished DNA polymerase activity. Blockage of the de novo pathway of DNA synthesis by the folate antagonist methotrexate (MTX) resulted in greatly increased flux through the thymidine salvage pathway and increased DNA polymerase activity but decreased 32PO4 incorporation in the transplantable hepatomas in Wistar rats fed normal zinc diets (50 micrograms/g feed). MTX had the effect of reducing all these activities in the groups fed low- and high-zinc diets. These data suggested a site of action of zinc associated with the salvage pathway of thymidine synthesis.
研究了锌对年轻雄性Wistar大鼠可移植性DAB肝癌生长的影响。锌缺乏（饲料中锌含量低于0.5微克/克）以及高剂量的膳食锌（500微克/克饲料）均显著降低肿瘤生长。高锌和低锌饮食均导致胸苷合成补救途径的活性降低，以及32PO4掺入DNA减少和DNA聚合酶活性降低。叶酸拮抗剂甲氨蝶呤（MTX）阻断DNA合成的从头途径，导致在喂食正常锌饮食（50微克/克饲料）的Wistar大鼠的可移植肝癌中，通过胸苷补救途径的通量大大增加，DNA聚合酶活性增加，但32PO4掺入减少。MTX对喂食低锌和高锌饮食的组中的所有这些活性都有降低作用。这些数据表明锌的作用位点与胸苷合成的补救途径有关。
