Fujiwara Y, Kaji T, Yamamoto C, Sakamoto M, Kozuka H
Department of Environmental Science, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.
Toxicology. 1995 Apr 12;98(1-3):105-10. doi: 10.1016/0300-483x(94)02984-3.
The effect of lead nitrate on the DNA synthesis of cultured bovine aortic smooth-muscle cells has been studied. Lead at 0.5-10 microM stimulated the incorporation of [3H]thymidine into the acid-insoluble fraction of the cells in a dose-dependent manner. However, other heavy metals including zinc, copper, manganese and nickel did not show such a stimulatory effect. Stimulation of [3H]thymidine incorporation by basic fibroblast growth factor was additive to that by lead. However, stimulation by either platelet-derived growth factor or acidic fibroblast growth factor was reduced by the metal. The leakage of lactate dehydrogenase into the medium from smooth-muscle cells, a marker of cell death, was not changed by the metal. Calcium ionophore A23187 inhibited [3H]thymidine incorporation in vascular endothelial cells but stimulated it in vascular smooth-muscle cells. These results suggest that lead may stimulate the proliferation of cultured vascular smooth-muscle cells probably via a calcium-dependent pathway; the metal may mimic calcium within the cells.
研究了硝酸铅对培养的牛主动脉平滑肌细胞DNA合成的影响。0.5 - 10微摩尔的铅以剂量依赖的方式刺激[³H]胸腺嘧啶核苷掺入细胞的酸不溶性部分。然而，包括锌、铜、锰和镍在内的其他重金属并未表现出这种刺激作用。碱性成纤维细胞生长因子对[³H]胸腺嘧啶核苷掺入的刺激作用与铅的刺激作用具有加和性。然而，血小板衍生生长因子或酸性成纤维细胞生长因子的刺激作用会被该金属降低。作为细胞死亡标志物的乳酸脱氢酶从平滑肌细胞泄漏到培养基中的情况并未因该金属而改变。钙离子载体A23187抑制血管内皮细胞中[³H]胸腺嘧啶核苷的掺入，但刺激血管平滑肌细胞中的掺入。这些结果表明，铅可能通过钙依赖途径刺激培养的血管平滑肌细胞增殖；该金属可能在细胞内模拟钙。
