Miyahara T, Yamada H, Ando R, Nemoto S, Kaji T, Mori M, Kozuka H, Itoh N, Sudo H
Toxicol Lett. 1986 Jul-Aug;32(1-2):19-27. doi: 10.1016/0378-4274(86)90044-5.
To clarify the effects of cadmium (Cd) on bone formation, a clonal osteogenetic cell, MC3T3-E1, was used in the present study. After 24 h of culture, Cd at 1 ppm and above decreased DNA synthesis and alkaline phosphatase activity, but Cd at 1.5 ppm caused no significant decrease in collagen content. The cells treated with Cd (0.03-1.0 ppm) for 24 h showed the dose-dependent effects on metallothionein-like protein synthesis. The marked increase of Cd content unbound to metallothionein (MT)-like protein with cadmium at 1 ppm may be responsible for the toxic effects of cadmium. After 10 days of culture, the accumulation of 45Ca to the cell layer decreased with increasing level of cadmium at 0.03 and 0.1 ppm. The cadmium-treated cell layer showed a weaker reaction to histochemical staining for mineral compared with control culture. This result suggests that Cd inhibits an initial process of calcification.
为阐明镉（Cd）对骨形成的影响，本研究使用了克隆成骨细胞MC3T3-E1。培养24小时后，1 ppm及以上的镉会降低DNA合成和碱性磷酸酶活性，但1.5 ppm的镉不会导致胶原蛋白含量显著降低。用0.03 - 1.0 ppm的镉处理细胞24小时后，对金属硫蛋白样蛋白合成呈现剂量依赖性影响。1 ppm镉处理下未与金属硫蛋白（MT）样蛋白结合的镉含量显著增加，这可能是镉产生毒性作用的原因。培养10天后，在0.03 ppm和0.1 ppm镉水平下，细胞层对45Ca的积累随镉水平升高而减少。与对照培养相比，经镉处理的细胞层对矿物质的组织化学染色反应较弱。这一结果表明，镉抑制了钙化的初始过程。
